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Writer's pictureBasil M Karatzas

Hull Survey Definitions, Terms & Terminology

Updated: Dec 25, 2021

Terminology for Marine Surveyors and other Maritime Professionals & Seafarers

Reference Material & Definitions incorporated, as applicable, in Marine Appraisals & Marine Survey Reports, prepared by Karatzas Marine Advisors & Co.


Abaft: A point beyond the midpoint of a ship’s length, towards the rear or stern.


ABS (American Bureau of Shipping): a vessel classification agency that also assigns international loadlines.


ABS Load Line Certification: An International load line certificated vessel that meets the requirements of the International Maritime Organization’s International Convention on Load Lines.

Abrasion: The removal of material by mechanical, i.e. rubbing or frictional, means.


Abrasion Test: A laboratory test to evaluate drilling-grade weighting material for potential abrasiveness. The test measures weight loss of a specially shaped, stainless-steel mixer blade after 20 minutes at 11,000 rpm running in a laboratory-prepared mud sample. Abrasiveness is quantified by the rate of weight loss, reported in units of mg/min. Mineral hardness, particle size and shape are the main parameters that affect abrasiveness of weighting materials. Some crystalline forms of hematite grind to a higher percentage of large particles than do other forms and are therefore more abrasive. Hematites are harder than barites, grind courser and are more abrasive. Thus, a hematite that is proposed as a weighting material for mud is typically a candidate for abrasion testing.


Access Holes: Holes cut in ship’s structure to permit entering or leaving various compartments.

Active Corrosion: Gradual chemical or electrochemical attack on a metal producing loose scale, by atmosphere, moisture or other agents.

Admeasure: To measure, calculate, and certify; for the purpose of registration, certain dimensions of a vessel as well as its gross and net tons.


Affreightment, Contract Of, (COA): An agreement by an ocean carrier to provide cargo space on a vessel at a specified time and for a specified price to accommodate an exporter or importer.


Aft: Movement toward the stern (back end) of a ship.


After Rake: The part of the stern which overhangs the keel.


AHP (Above Head of Passes): used with mileage designations on the Mississippi River, the Head of Passes being mile zero.


AIWW: Atlantic Intracoastal Waterway.


All Fast: he time during which the Vessel is completely moored, which includes gangway down and secured (for all Vessels other than Inland Barges), at the Cargo Transfer Point.


All Hands: The entire crew.


All In: The total price to move cargo from origin to destination, inclusive of all charges.


All Standing: To bring to a sudden stop.


Alleyway: A vessel’s internal passageway or corridor.


Allowable Corrosion or Wastage Limit: The acceptable thickness diminution of structural elements.


Aloft: Above the upper deck (above).

Alongside: A phrase referring to the side of a ship. Goods delivered “alongside” are to be placed on the dock or barge within reach of the transport ship’s tackle so that they can be loaded.


Alteration: Change that does not affect the basic character or structure of the ship to which it is applied.This is typically a limited change to the ship's structure, equipment or functions, such as change of components, change of local structure, change of draught or change of class notations not affecting ship's purpose/type.


AMVER: Automated Mutual-Assistance Vessel Rescue System


Anchor Watch: The detail on deck at night, when at anchor, to safeguard the vessel (not necessarily at the anchor; a general watch).


Anchor Handling Tug Support Vessels (AHTS): Specialist vessels designed for towing and/or anchor handling. Predominantly employed in the movement of rigs and platforms, and for the handling and laying of their anchors. Anchor Handling Tug Supply (AHTS) vessels combine the role of supply vessels and anchor handling tugs. They are the backbone of offshore operations and constitute the largest proportion of offshore vessels. Not only do they deliver supplies such as deck cargo, water, fuel, dry bulk and mud to oil rigs and platforms, they are specially designed to provide anchor handling services, towage duties and in some cases also serve as an Emergency Towing Rescue and Recovery Vessel (ETRRV). Some modern AHTS vessels are also equipped for fire fighting, rescue operations and oil recovery to enable them to have a more multi-role capability.

Anode: The positively charged metal surface and the corroding part of an electrochemical corrosion cell at which the oxidation or loss of electrons occurs. Sacrificial anode or impressed current anode. Also, Sacrificial Anode.

Antifouling: Paint for use on underwater areas on hulls. Antifouling contains agents who prevent the adhesion and growth of organisms on the hull.


API-MPMS: The American Petroleum Institute Manual of Petroleum Measurement Standards, as such may be amended and/or updated from time to time.


Arkansas River Lock and Dam 1 (Located in Tichnor, AR at mile 10 on the Arkansas River): This is a single chamber lock that is 600 ft. by 110 ft. in dimension (also called Norrell Lock).


Asdem Pumping Performance Formula: The formula maintained by Asdem and used to assess underperformance by a tanker’s pumps during discharge of cargo. The formula can be found on Asdem’s website at: http://www.asdem.co.uk/.


Astern: Behind a vessel; or, move in a reverse direction.


Atlantic: A grain export region that includes export elevators in Brunswick, GA, Albany, NY, and Chesapeake, VA.


ATDNSHINC: Any Time Day or Night Sundays & Holidays Included.


ATUTC: Actual Times Used to Count


Athwartship: Transverse or across a vessel from side to side or a direction across the width of a vessel.


Automated Identification System (AIS): An electronic instrument placed on regulated powered vessels to automatically provide their identity, location and other navigational data to a central receiving base to facilitate navigational control and safety.


Auxiliary Lock: The smaller chamber of a double lock that transfer vessels from one water level to another water level. The advantage of this two-lock facility is that both chambers can be working at the same time, and more importantly while one chamber is closed for repairs, the other chamber can handle the traffic. See Main Chamber Lock.


Avast: An order to stop or cease hauling (stop action at once).


Avoirdupois weight (n): the series of units of weight based on the pound of 16 ounces and the ounce of 16 drams

Awash: Level with the water (water ready to, or slightly covering decks).


AWWL: Always Within Institute Warranties Limits (insurance purpose).


Backhaul: To haul a shipment back over part of a route it has traveled.


Bacterial Corrosion or Microbially Influenced Corrosion (MIC) is corrosion which is induced or accelerated by the presence of micro organisms.


Ballast: Any substance, other than cargo, which is usually placed in the inner compartment of a vessel to produce a desired draft or trim.


Bareboat Charter (Demise Charter): A form of vessel rental in which the charterer assumes total responsibility for the vessel and its operations, as if the vessel was owned by the charterer.


Barge: A large, flat-bottomed, rigged or unrigged, craft of full body and heavy construction, specially adapted for the transportation of bulk freight such as grain, ethanol, fertilizer, coal, lumber, oil etc. from a port to shallow-draft waterways. Barges have no locomotion and are pushed by towboats. A single, standard barge can hold 1,500 tons of cargo or as much as either 15 (jumbo hopper) railroad car or 58 large grain hopper semi-trailers or 60 truckloads. A barge load of grain, as a unit of measure is 52,500 bushel . A jumbo covered hopper barge is the type of barge most frequently used for moving grain on the rivers. A barge is 200 feet long, 35 feet wide and has a draft of 9 feet. Barges carry dry bulk (grain, coal, lumber, gravel, etc.) and liquid bulk (petroleum, vegetable oils, molasses, etc.).


Barge, Inland: A USCG- or American Bureau of Shipping-inspected and approved tank barge that is restricted to operations in the inland waterways of the US.


Barge, Jumbo Covered Hopper: Type of barge most frequently used for moving grain on the rivers. Older barges held 52,500 bushels, but some newer barges have larger capacities.


Ocean Barge or Ocean-Going Barge: A USCG- or American Bureau of Shipping-inspected and approved tank barge that has an ABS Load Line Certification and is certified to operate in offshore waters.


Barges Unloaded: The number of barges of grain unloaded in the area between Baton Rouge New Orleans, LA.


Barrel (and BBL): 42 US Gallons measured at 60 degrees Fahrenheit (60°F).


Base Rate / Freight Rate: A tariff term referring to ocean rate less accessorial charges, or simply the base tariff rate.


Beam: The breadth of a vessel.


BENDS: Both Ends (Load & Discharge Ports)

BEP: Best Environmental Practice.


Bentonite: A material composed of clay minerals, predominantly montmorillonite with minor amounts of other smectite group minerals, commonly used in drilling mud. Bentonite swells considerably when exposed to water, making it ideal for protecting formations from invasion by drilling fluids. Montmorillonite forms when basic rocks such as volcanic ash in marine basins are altered.


BIMCO: Baltic & International Maritime Council


Blasting or Shot-Blasting: The cleaning of a metal surface by a stream of abrasive particles.

Blister: A raised area, often dome shaped, resulting from loss of adhesion between a coating or deposit and the substrate.


BNWAS: Bridge Navigational Watch Alarm System


Bollard Pull: The static pulling force of a tugboat measured in pounds/tons.


Bone in her teeth: A colloquial phrase implying that a boat is moving through the water at considerable speed. The "bone" is the bow wave thus produced.


Bosom: The inside of an angle bar.


Bound (Fogbound): Immobilized by heavy fog.


Bound (Windbound): When a tow stops due to high wind and the boat does not have enough power to keep the tow moving.


BPG: Bridge Procedures Guide

BPQ: Barge Particulars Questionnaire


Breakbulk Cargo: Non-containerized general cargo stored in boxes, bales, pallets or other units to be loaded onto or discharged from ships or other forms of transportation. (See also: bulk and container.) Examples include iron, steel, machinery, liner-board and wood pulp.


Breaming: Cleaning the barnacles, paint, etc., from a ship’s bottom with a blow torch.


Bridge Transit Decision Points: Decision points in passage plans describe places or times when vessels must take action to avoid hazardous conditions. Such decision points should allow enough time and distance to safely execute a contingency plan. Passages that include lift and swing bridges must anticipate and account for delayed openings, especially in high-current scenarios.


Bridle: A V-shaped chain, wire, or rope attached to a vessel being towed to which the towline is connected. A short length of wire with a line attached at the midpoint. A bridle is used to distribute the load of the attached line. Often used as boom travelers and for spinnaker down hauls.

Bright Work: Varnished woodwork or polished metal.


Brittle Fracture is the separation of a solid accompanied by little or no macroscopic plastic deformation. Typically, brittle fracture occurs by rapid crack propagation with less expenditure of energy than for ductile fracture. Brittle tensile fractures have a bright, granular appearance and exhibit little or no necking.

Buckling: a bulge bend or other wavy condition of the structure caused by in plane compressive stresses and /or shear stresses.


Bulk Cargo: Loose cargo (dry or liquid) that is loaded (shoveled, scooped, forked, mechanically conveyed or pumped) in volume directly into a ship’s hold; e.g., grain, coal and oil.


Bulwark: The side of a vessel that extends above the upper deck.


Buoy: A stationary floating object used as an aid for navigation.


Buoyancy: Ability to float, lifting power when immersed.


Burr Edge: The rough uneven edge of a punched or burnt hole or plate.


Bushel: A unit of measure containing 2,150.42 cubic inches, 56 pounds of corn, or 60 pounds of wheat or soybeans.


Butt Joint: A joint between two structural members lying in the same plane. Typically a butt joint is used to describe the welded connection between two plates in the transverse direction.


Butt Strap: A bar or plate used to fasten two or more objects together with their edges butted.


Butterworth: A washing process used to gas free or clean a cargo tank, by means of hot water or chemicals, sprayed through a patented rotating nozzle.


Butterworth Opening: A deck access opening with bolted cover, designed for butterworth operations.


By the Head: Deeper forward (front end deepest in water).


By the Lee: Sailing downwind with the wind blowing over the leeward side of the boat, increasing the possibility of an unexpected jibe.


Cable Laying Vessel: A Cable Laying Vessel (cable layer or cable ship) is a sea going vessel specially designed to lay underwater cables (telecommunications, electric power transmission, or other). Р’ The newest design of cable layers is a combination of cable-laying and repair ships, so they are also able to retrieve broken or damaged sub-sea cables and repair them on board. Depending on water depth and the risk of potential damage, sub-sea cables are buried in the sea floor by the cable layer using a special plough. A DP 2 system enables the vessel to remain in a precise position above the defined cable route.

Cabotage: Shipment of cargo between a nation’s ports is also called coastwise trade. The U.S. and some other countries require such trade to be carried on domestic ships only.


Camber: The upward slope of a vessel’s deck, occurring when the centerline is higher than the gunwale.


Cant: The inclination of an object from the perpendicular. As a verb, to turn anything so that it does not stand square to a given object.

Cant Beam: Any of the beams supporting the deck plating or planking in the overhanging part of the stern of a vessel. They radiate in fan shape from the transom beam to cant frames.

Cant Body: The portion of a vessel’s body either forward or aft in which the planes of the frames are not at right angles to the center line of the ship.

Cant Frame: Hull side frame not aligned perpendicular to the vessel’s centerline.

Cant Frames: The frame (generally bulb angles) at the end of a ship which are cented, that is, which rise obliquely from the keel.


Car, Jumbo Hopper: A rail car with a 3,500-bushel capacity, and a 100 ton grain capacity.


Cargo Quantity: The volume or quantity of the Cargo that is either loaded or discharged at the Cargo Transfer Point and that is specified in the charterparty and/or B/L. Cargo Transfer Point: The location specified in the charterparty where custody of the Cargo is transferred from Seller to either Buyer or Buyer’s designee.

Cathode: The negatively charged metal surface and the non-corroding or protected part of an electrochemical corrosion cell.

Cathodic Protection: The partial or complete protection of a metal from corrosion by making it a cathode, using either a galvanic or an impressed current to bring a metal to a potential where it is thermodynamically stable.


Cavitation: The formation of bubbles on an aerofoil section in areas of reduced pressure. Can occur on heavily loaded ship propellers.

Cavitation Damage: Degradation of metal surfaces, characterized by pitting, in which the pit profile is irregular, occurring when very turbulent fluids are in contact with the metal surface, and associated with the formation and collapse of cavities in the liquid at the solid – liquid interface.


Center of Buoyancy (CB): The point through which the buoyancy force acts. It is defined in space by its longitudinal, vertical and transverse (respectively, LCB, VCB and TCB) position relative to a set of orthogonal axes. It is also the centroid of volume of the displaced water. Center of Flotation (CF): The centroid of area of a waterplane. A small weight added, or removed, from the ship vertically in line with the CF will cause a change of draught without heel or trim. For a symmetrical ship the CF will be on the centerline and its position is given relative to amidships. Center of Gravity (CG): The point through which the force due to gravity, that is the weight of the body, acts. Its position is defined in a similar way to the center of buoyancy and is very important in calculations of stability. The point of equilibrium of the total weight of a containership, truck, train or a piece of cargo. Centerline: The longitudinal vertical plane of a vessel.


CERCLA (Comprehensive Environmental Response, Compensation and Liability Act): The U.S. federal statute that establishes the legal and financial responsibilities of those persons or companies that discharge or dispose of hazardous substances on or into land, air, and navigable waters of the U.S. Primarily administered by the U.S. Environmental Protection Agency.


Certification: The act of attesting that a vessel has met specific legal requirements by the issuance of various certificates or validation of documents by certain governmental or private agencies.


CFR: The US Code of Federal Regulations. U.S. Code Title 46 - Shipping and CFR: Title 33. Navigation and Navigable Waters.


Chain of Rocks Locks (Located in Granite City, IL at mile 186 on the Upper Mississippi River): This double lock includes a 1200 ft. by 110 ft. main lock chamber and 600 ft. by 110 ft. auxiliary lock (also called Mississippi River Locks 27).


Channel: That portion of a waterway that is naturally or artificially deepened to permit safe navigation within certain limits.


Charter Party: A contractual agreement between two entities for the purpose of renting, hiring, or leasing the exclusive use of a vessel.


Charterer: The person or entity hiring the performing Vessel.


Chock: A piece of wood or other material put next to cargo to prevent it from shifting.


CIF (Cost, Insurance, and Freight): Cost of transportation and insurance to be paid by the seller of goods to the named point of destination.


Classification: The certification process, as administered by certain international agencies, whereby a vessel is designed, constructed, and maintained, in accordance with an agency’s requirements.


CLC: Civil Liability Convention of 1969, as such has been amended from time to time.


Clip: A small steel bracket used for securing or reinforcing.


Clipper Bow: A bow with an extreme forward rake, once familiar on sailing vessels.


Close-up Survey: A survey where the details of structural members are within the close visual inspection range of the surveyor, i.e. normally within the reach of hand.


COACP: Contract of Affreightment Charter Party


Coating Evaluation Criteria: Normally an assessment of the extent of damage registered in terms of coating breakdown area and/or rust scales in % of area under consideration, normally the complete tank, with additional information on coating damage to edges and weld connection. Typical coating failures may be given as additional information.

Coating, often synonymous with Painting, i.e. a protective film of thickness usually about 0,2 - 0,5 mm, applied to prevent corrosion mainly via a three main mechanisms; the barrier effect, the cathodic effect or by inhibition / passivation.


COC: Certificate of Compliance.


Coefficients of Fineness: These relate to the underwater form and give a broad indication of the hull shape. They are the ratios of certain areas and volumes to their circumscribing rectangles or prisms.


Cofferdam: The space in a vessel between two closely located parallel bulkheads.

Collision Damage: Damage caused by physical impact between two or more ships used for navigation.


Collision Mat: A large mat used to close an aperture in a aperture in a vessel’s side resulting from a collision.


Comehome: A convex curvature of the rake sides of a barge that produces a narrower beam at the headlog than the beam of the hull.


Common Carrier: A federally licensed company that offers to the general public, under published tariffs, to engage in the interstate or foreign transportation of commodities of various types.


Companionway (Sailing Boat): The main entrance to the cabin, usually including the steps down into the cabin. A passageway through which a ladder or stairs lead from the deck down to the cabin.


Compartment: An interior space of a vessel’s hull formed by bulkheads.

Condition Assessment Program (CAP): A voluntary system, which gives a detailed assessment of a tanker’s actual condition at the time of inspection and is available to both charter-parties and owners. CAP is a voluntary program, initially developed by the oil industry, to assess the continued fitness of older ships to carry their cargo safely. CAP involves a detailed survey, including gauging of the vessel’s structure and a sophisticated strength and fatigue engineering analysis. It also includes extensive testing of the vessel’s machinery, equipment and cargo systems. A CAP rating is assigned to the vessel. A CAP 1 (Very Good) or CAP 2 (Good) rating is required by most charterers. Both of these ratings suggest that the vessel has been maintained to a standard in excess of Classification Society and Statutory minimums.

Condition Survey: A survey normally of limited scope and time and intended to identify any anticipated structural or corrosion related deficiencies and give an overall visual impression of the structural integrity.


Condition Rating Terms:

* ABOVE AVERAGE (GOOD): Condition unimpaired without significant wear of deviation from original strength and operating efficiency. No maintenance or repair required.


* AVERAGE (FAIR) : Condition with tear and fear and other deficiencies of minor nature not requiring correction or repair.


* BELOW AVERAGE (POOR): Condition in which the adequacy of strength and/or operational efficiency if marginally below acceptable limits or is in doubt. Remedial action is required.


* UNSATISFACTORY: Condition of undoubtedly inadequate strength or operational efficiency immediate extensive repair or renewal required to reinstate serviceability.


Confirmed Letter of Credit: A letter of credit, issued by a foreign bank, whose validity has been confirmed by a domestic bank. An exporter with a confirmed letter of credit is assured of payment even if the foreign buyer or the foreign bank defaults.


Contact Damage: Damage caused when the ship strikes something other than another ship. (see also ‘Grounding’).


Container: An intermodal uniform, sealed, reusable metal “box” (generally 40 feet in length, able to hold about 40,000 pounds) in which merchandise can be moved by either, rail, barge, truck or vessel. The use of containers (or containerization) in trade is generally thought to require less labor and reduce losses due to breakage, spoilage, and pilferage, compared to more traditional methods of shipment. Containers come in 53, 48, 45, 40 and 20 foot lengths, and are anywhere between 8, 8.5, 9 and 9.5 feet in height. Width is eight foot. Container Load: A load sufficient in size to fill a container either by cubic measurement or by weight. Containerizable Cargo: Cargo that will fit into a container and result in an economical shipment. Containerization: Stowage of cargo in a container for transport in the various modes. See Container.

Contour Line: A line on a chart connecting points of equal depth or elevation.


Contract Carrier: A federally licensed company that offers, under individual contracts, to engage in interstate or foreign transportation of commodities of various types.


Conversion: Change that substantially alters the main dimensions (L, B, D), watertight subdivision, carrying capacity, engine power or ship type. Increased draught is normally not regarded as a conversion. However, precaution should be taken if the increase in draught is major.


COFR (Certificate of Financial Responsibility): a document issued by U.S.C.G. to a company for a vessel or a fleet of vessels, giving evidence that the vessel owner/operator has met the financial requirements for oil spill clean-up costs as contained in the Oil Pollution Act of 1990.

COGSA (Carriage of Goods by Sea Act): U.S. federal codification passed in 1936 which standardizes carrier’s liability under carrier’s bill of lading. U.S. enactment of the Hague Rules.


Corn: Corn varieties include: U.S. No. 1-5 and Sample Grade, Yellow, White, and Mixed Corn as defined by USDA's Grain Inspection, Packers and Stockyards Administration. Corn #1: The highest grade of corn, distinguished by the highest minimum test weight, lowest moisture and foreign material, and the fewest damaged kernels. Marketed primarily as food. Corn #2: Most frequently traded of all grades (about 60 percent of all corn sold), and the grade on which the traded price is based. It is used primarily for animal feed. Grades 3, 4, 5, and Sample are lower grades than #2. Sample Grade is the lowest grade available.


Corrosion Fatigue: The process in which a metal fractures prematurely in a trans- crystalline manner under conditions of simultaneous corrosion and repeated cyclic loading of lower stress levels or fewer cycles than would be in the absence of a corrosive environment

Corrosion is the chemical or electrochemical reaction between a material, usually a metal and its environment that produces a deterioration of material and its properties, usually an oxide is formed.

Corrosion Prevention System is considered a full hard coating; alternatively a full hard coating supplemented by cathodic protection.


COTP: Captain of the Port.

Crack: A fracture type discontinuity without complete separation characterized by a sharp tip and high ratio of length and width to opening displacement.


Craft: A boat, ship or airplane.


Crevice Corrosion: Localized corrosion of a metal surface at, or immediately adjacent to, an area that is shielded from full exposure to the environment because of close proximity between the metal and surface of another material. It is usually associated with small volumes of stagnant water; within lapped joints, under heads of fastenings, under gaskets and packings, under marine organisms and porous deposits.

Critical Structural Areas: Locations which have been identified from calculations to require monitoring or from the service history of the subject ship or from similar ships to be sensitive to cracking, buckling or corrosion which would impair the structural integrity of the ship.


Crossing the Line: Crossing the Equator.

Cumulative Damage: An aggregation of damage due to various physical causes, specifically applied to fatigue under various stress ranges and frequencies.


Customary Anchorage: The recognized anchorage for or within the designated port for the Cargo Transfer Point (that may be specified in the charterparty).


Customs: A duty or tax on imported goods. The Customs Department also works to prevent the importation of illegal drugs and contraband.


Customs Broker: This person prepares the needed documentation for importing goods (just as a freight forwarder does for exports). The broker is licensed by the Treasury Department to clear goods through U.S. Customs. Performs duties related to documentation, cargo clearance, coordination of inland and ocean transportation, dockside inspection of cargo, etc. (Also known as a customhouse broker.)


D & A Policy: Any applicable Drug and Alcohol abuse policy.


Damage Survey: A survey requested as a result of hull damage or other defects.


Daymark: A marker used as an aid to navigation and which is visible in daylight.


DCV: Debris (or Drift) Collection Vessel


Dead Ahead: Directly ahead on the extension of the ship’s fore and aft line.


Deadhead: One leg of a move without a paying cargo load. Usually refers to repositioning an empty piece of equipment.


Deadman: An object, such as an anchor, piling, or concrete block, buried on shore.


Deadrise: The upward slope of a vessel’s bottom occurring when the centerline is deeper than the bilge knuckle; provided to facilitate removal of liquid cargo.


Deadweight: The number of tons of 2,240 pounds that a vessel can transport of cargo, stores and bunker fuel. It is the difference between the number of tons of water a vessel displaces “light” and the number of tons it displaces when submerged to the “load line”. The carrying capacity of a ship in metric tons, including the weight of fuel and stores as well as the cargo. The cargo capacity of a ship is generally estimated as 95 percent of deadweight capacity for large tankers and 85 percent of deadweight capacity for dry cargo container ships.


Deadweight Cargo: A long ton of cargo that can be stowed in less than 40 cubic feet.


Deadweight Tonnage: The cargo capacity of a vessel.


Deck Barge: Transports heavy or oversize cargoes mounted to its top deck instead of inside a hold. Machinery, appliances, project cargoes and even recreational vehicles move on deck barges.


Deck Button: A round, steel fitting affixed to a vessel’s deck, designed to secure or guide cables for making up barge tows.


Dedicated Tow: Movement of barge(s) between two points by the use of a boat exclusively assigned to that movement. A “dedicated” boat offers greater control of barge movements than a “tramp” tow, but generally at a higher cost.


Deepwater Construction Vessel (DCV): DCV vessel is capable of executing complex infrastructure and pipeline projects in ultra deep water, while offering sufficient lifting capacity to install platforms in relatively shallow water. These vessels are capable of operating in waters beyond 3,000 meters. They used for the installation of foundations, moorings, SPARs, TLPs, and integrated topsides, as well as pipelines and flowlines. As a rule, deepwater construction vessels are outfitted with DP2 or DP3 technology for operations in very harsh environments. DCV are equipped with powerful offshore cranes and ROV work class systems. On biggest DCVs the living quarters can accommodate up to 500 persons in single and double cabins or even up to 700 (like on DCV “Thialf”, Heerema).


Delivery Window: The period during which the Vessel nominated by or on behalf of Buyer or Seller under the Agreement is to present itself at the Cargo Transfer Point, as established by the charterparty and is within the contract delivery date range set forth in the Agreement.


Demurrage: A charge assessed for detaining a vessel beyond the free time stipulated for loading or unloading. A penalty fee assessed when cargo isn’t moved off a wharf before the free time allowance ends.


Detention: The period of time that an owner or charterer is deprived of the use of his vessel as a result of actions of another party (usually a party with statutory authority such as the Coast Guard.


Deformation: A change in the form of a structure due to stress, thermal change, change in moisture, or other causes.

Delamination: Peeling from undercoat or substrate.

Deposit Attack: An attack under, or around, the edge of a local deposit formed on a metal surface in the presence of an electrolyte.


Derelict: A vessel abandoned and drifting aimlessly at sea.


Derrick [Drilling]: The structure used to support the crown blocks and the drillstring of a drilling rig. Derricks are usually pyramidal in shape, and offer a good strength-to-weight ratio. If the derrick design does not allow it to be moved easily in one piece, special ironworkers must assemble them piece by piece, and in some cases disassemble them if they are to be moved.


Diameter - Outside Diameter (OD): Outside or outer diameter. Casing and tubing are commonly described in terms of inside diameter (ID) and outside diameter. Diameter - Inside Diameter (IS): Inside or inner diameter. Casing, tubing and drillpipe are commonly described in terms of inside diameter and outside diameter.


Differential: An amount added or deducted from base rate to make a rate to or from some other point or via another route.


Dinner Bucket Boat (also Lunch Bucket Boat): A boat that does not have a galley or only has limited crew quarters. These boats generally work daylight hours only.


Displacement: The weight, in tons of 2,240 pounds, of the vessel and its contents. Calculated by dividing the volume of water displaced in cubic feet by 35, the average density of sea water. Weight of the Ship = Volume of Water Displaced (Displacement) × Density of Water. The water that is displaced by the ship equals the volume of the ship that is submerged, and we can rewrite the equation as, Weight of the Ship = Submerged Volume of the Ship (Displacement) × Density of Water.


Ditty Bag: A bag used by sailors to hold gear needed for repairs on sails or rigging.


Diving Support Vessel (DSV): Diving Support Vessel (DSV) is designed for diving operations carried out below and around oil production platforms and related installations in open waters. These vessels are used for underwater repair, inspection, construction works, well intervention and etc. Most of the modern DSV vessels designed for efficient diving operations in harsh environments.


Dock: (verb) - To bring in a vessel to tie up at a wharf berth. (One parks a car, but docks a ship.) (noun) - A dock is a structure built along, or at an angle from, a navigable waterway so that vessels may lie alongside to receive or discharge cargo. Sometimes, the whole wharf is informally called a dock.


Dockage: A charge by a port authority for the length of water frontage used by a vessel tied up at a wharf.


Docking Plan: Detailed structural plan and profile of the lower hull structure required for correct location of the vessel in dry docking.


Docking Tug: A tugboat that assists a large seagoing vessel to and from its berth.

Documentation: The process of licensing a vessel in either enrollment or registry, resulting in the issuance of a vessel’s official document.


Dog Shores: The last supports to be knocked away at the launching of a ship.

Doldrums: The belt on each side of the Equator in which little or no wind ordinarily blows.


Dolphin (Mooring Dolphin): A cluster of piles driven into the bottom of a waterway and bound firmly together for the mooring of vessels.


DOS: A Declaration of Security as provided for under the ISPS Code.


Double-rake Barge: A barge that neither its bow or stern is square. Double-skin Barge: A barge with a void space between the cargo tanks and the hull.


Doubler: A steel plate installed on an existing structural plate and used as a strengthening base for deck fittings or as a repair of a damaged area. A wood or metal plate bolted beneath a mounting surface for reinforcement.


Downwind: Sailing in the same direction as the wind.

Draft: The depth of a vessel’s keel below the waterline; often expressed as light-draft; or, conversely, loaded draft.


Draft Marks: The numerical markings on the sides of a vessel at the bow and stern, which indicate, at the lower edge of the number, the amount of water the vessel draws.


Drayage: Transport by truck for short distances; e.g. from wharf to warehouse.


Dredge (Backhoe Dredge)

A backhoe is a type of grab crane dredging pontoon. It consists of a hydraulic grab crane mounted on a dredging pontoon. The dredging pontoon is usually held in place by three spud poles. Backhoes are used to dredge heavy clay, soft stone, blast rock and soil thought to contain boulders, for example in foreshore protection operations.


Dredge (Cutter Suction Dredge (CSD))

A cutter suction dredge (CSD) sucks dredged material through the intake pipe at one end and then pushes it out the discharge pipeline directly into the placement site. Since a CSD pumps directly to the placement site, it operates continuously and can be very cost-efficient. Most CSDs have a cutterhead on the suction end. A cutterhead is a mechanical device that has rotating blades or teeth to break up or loosen the bottom material so that it can be sucked through the dredge. Some cutterheads are rugged enough to break up rock for removal. A CSD is mounted (fastened) to a barge, not usually self-powered, towed to the dredging site, and then secured in place by special anchor piling, called spuds (see sidebar).

A CSD is able to work in a range of water depths and has the ability to dig its own flotation if the existing ground is very shallow or above water. It’s very efficient in areas with thick shoals, where the cutterhead is buried in the bottom. Water pumped with the dredged material is generally contained in the placement site until the solids settle out. Once settled, the water is generally returned to the waterway.

A CSD comprises the cutterhead, the spuds, the pipeline and the pontoons to float the pipeline. The connection of the spuds and cutterhead to the waterway floor, along with the floating pipeline, may sometimes limit a CSD’s ability to maneuver during inclement weather conditions.

CSD operators can adjust their approach to projects depending on the season by using anchors to help “walk” the vessel forward and efficiently utilize the floating pipeline. Dredge (Cutter Suction Dredge)

A cutter suction dredger is a stationary or self-propelled vessel that uses a rotating cutter head to loosen the material in the bed (‘cutting’). A suction inlet located beneath the cutter head (known as the suction mouth) is connected by a suction tube directly to one or more centrifugal pumps. The vacuum force at the suction inlet sucks up the loosened material. The suction tube and cutter head are attached to a ladder. The ladder with cutter head is positioned at the fore of the vessel. On the aft side, the cutter generally has two spud poles. One spud pole (the auxiliary spud) passes straight through the vessel, while the other is mounted on a movable spud carriage, which can be moved lengthwise along the vessel or pontoon. Steel cables are used to move the ladder or cutter head back and forth, with the spud in the spud carriage as the center of each concentric circle that it describes. Moving the spud carriage causes the cutter suction dredger to move as well (‘stepping’). The cutter suction dredger discharges the dredged material directly to shore via a floating pipeline or into a barge with a special loading system.


Dredge (Hopper Dredge)

A hopper dredge is well-suited for dredging materials ranging from soft mud and silt to dense sands and clay. It can maintain operations in relatively rough seas and because of its mobility be used in high-traffic areas. It is often used at ocean entrance channels and is very productive in deep water and wide open spaces. A hopper dredge is nimble and can transit quickly to dredged material placement sites under its own power without the need for tug assist or towing.


Dredge (Hydraulic Dredge)

A hydraulic dredge works by sucking a mixture of dredged material and water from the channel bottom. The amount of water sucked up with the material is controlled to make the best mixture. Too little water and the dredge will bog down; too much and the dredge won’t be efficient in its work. There are two main types of hydraulic dredges – hopper dredges and cutter suction dredges.

Dredge (Mechanical Dredge)

A mechanical dredge removes material by scooping it from the sea floor and placing it into a barge or an approved placement area. Dipper, backhoe and clamshell dredges are types of dredges that are suitably named in accordance with their scooping buckets.

Mechanical dredges are rugged and can work in tightly confined areas. They are mounted on a large barge, towed to the dredging site, and secured in place by anchors or anchor pilings (otherwise known as spuds). Mechanical dredges are often used in harbors, near docks and piers, and in relatively protected channels. Usually two or more disposal barges, called scows, are used in conjunction with a mechanical dredge. The operation generally consists of a series of barges. While one barge is filled with material, another barge transits to the placement site and then returns to repeat the cycle, allowing for near continuous and uninterrupted operations. Mechanical dredges are particularly efficient on dredging projects where the placement site is several miles away.

Clamshell dredges are designed to handle loose to medium dense soils and dredge materials, while backhoe and dipper dredges are used to remove consolidated or hard-packed materials and can also be used to clear rock and debris. Hooded or enclosed buckets are utilized to control the flow of water and to prevent contaminated sediments from seeping back into the water column.



Dredge (Trailing Suction Hopper Dredge)

A trailing suction hopper dredger has large, powerful pumps and engines that enable it to suck up sand, clay, sludge and even gravel from ocean or river beds. One or two suction pipes run from the vessel to the bed. A draghead is attached to the end of the pipe and lowered to just above the bed, making it possible to regulate the mixture of sand and water that it takes in. A trailing suction hopper dredger generally stores the dredged material in its own hopper and discharges the left-over water overboard. A trailing suction hopper dredger can empty its hopper in a variety of different ways: a) Depositing - Opening doors or valves on the bottom of the vessel so that the hopper contents drop out. b) Pumping - Using jet pumps or water jets to pump water into the hopper at high pressure so that the sand becomes ‘fluid’ again. The dredge pumps can then pump the resulting mixture through a pipeline which is connected to the vessel. c) Rainbowing - This method is the same as pumping, except that the hopper contents are not pumped through a pipeline, but are sprayed over the vessel’s bow directly at the desired location.

Dredge (Water Injection Dredge)

Water injection dredgers are often used in small, shallow ports and marinas because they have good manoeuvrability and can dredge very close to embankments and quay walls. An injection beam located underneath the vessel injects large volumes of water under low pressure into silt or fine sand in order to resuspend it. The sediment mixture turns into a density current, which is then removed with the help of gravity. Some water injection vessels are built as demountable pontoons.


Dressing Ship: A display of national colors at all mastheads and the array of signal flags from bow to stern over the masthead (for special occasions and holidays).

Drift Angle: The angle between a ship’s head and the direction in which it is moving.


Drilling Mud [Mud, Drilling Fluids]: Any of a number of liquid and gaseous fluids and mixtures of fluids and solids (as solid suspensions, mixtures and emulsions of liquids, gases and solids) used in operations to drill boreholes into the earth. Synonymous with "drilling fluid" in general usage, although some prefer to reserve the term "drilling fluid" for more sophisticated and well-defined "muds." Classifications of drilling fluids has been attempted in many ways, often producing more confusion than insight. One classification scheme, given here, is based only on the mud composition by singling out the component that clearly defines the function and performance of the fluid: (1) water-base, (2) non-water-base and (3) gaseous (pneumatic). Each category has a variety of subcategories that overlap each other considerably.


Drip Pan: An open container located on deck under the ends of a pipeline header to retain cargo drippage. Required on all U.S.C.G.-certified tank barges.


Dry Dock: (1) A dock into which a vessel is flated, the water than being removed to allow for the construction or repair of ships. Large basin with sealing caisson for the repair and maintenance of vessels. (2) General term for basin dry docks, floating docks or lift platforms for the maintenance and repair of vessels.


Drydocking: The removal of a vessel from the water to accomplish repairs or inspections.


Duck Pond: An opening in a tow where vessels join together, that a person could fall through, and land into the water.


Ductile Fracture: The separation of a solid accompanied by gross plastic deformation.


Ductility: The property of a metal which permits its being drawn out into a thread or wire.


Dumb Vessel: A vessel without means of self-propulsion.


Dump Scow (Split-Hull Dump Scow) Barge: Barges for the shipment of materials such as sand, soil, waste and dredged material. The differentiating design feature of a dump scow is the ability to release contents through the underside of the barge by hinging the barge open to dump the cargo.


Dunnage: Any materials used to block or brace cargo to prevent its motion, chafing, or damage and to facilitate its handling.


East Gulf: A grain export region, which includes the export elevator in Mobile, AL.


Eddy: Indicated turbulence of the water.


Edge Corrosion: Local corrosion at the free edges of stiffeners, brackets, flanges, manholes etc.


EHL (East of Harvey Lock): Used with mileage designations on the Gulf Intracoastal Waterway, Harvey Lock being mile zero.


Elasticity: The structural member's capability of sustaining stress without permanent deformation, i.e. to recover its original size and shape after the stress has been removed.

Electrochemical Corrosion: Corrosion associated with the passage of an electric current. If the current is produced by the system itself it is called Galvanic Corrosion and if it results from an impressed current it is called Electrolytic Corrosion.


Electronic Data Interchange (EDI): The exchange of information through an electronic format. Electronic commerce has been under intensive development in the transportation industry to achieve a competitive advantage in international markets.


Endurance: Maximum time period (indicated in hours or days) that a vessel can operate unreplenished while performing its intended role.


EPA: The US Environmental Protection Agency, and any successor Governmental Authority.


EPIRB (Emergency Position Indicating Radio Beacon): EPIRB is a small hand-held battery-operated transmitter, actuated by water, for use in locating vessels in distress. EPIRBs are devices that trasmit a digital signal on the international distress signal frequency 406 MHz. Designed to work with satellites, EPIRBs are detectable by COSPAS-SARSAT satellites, which orbit the poles, and by the GEOSAR system which consists of GOES weather satellites and other geostationary satellites. There are two types of EPIRBs, Category I or Category II. Category I EPIRBs float-free and are automatically activated by immersion in water, and they are detectable by satellite anywhere in the world. Category II EPIRBs are similar to Category I, except in most cases they are manually activated, however some models can be automatically activated.


Erosion Corrosion: A combined action involving corrosion and erosion in the

presence of a moving corrosive fluid, leading to the accelerated loss of material. Erosion corrosion is characterized by grooves, gullies, waves, valleys etc., usually with

directional pattern and with bright surfaces free from corrosion products.

Erosion Damage is the physical removal of material from a surface by mechanical means such as e.g. flowing liquid and it may be accelerated by corrosion.


ETA: Estimated Time of Arrival.


ETD: Estimated Time of Departure.


Excessive Corrosion: Extent of corrosion that exceeds the Allowable Corrosion.

Extensive Corrosion is an extent of corrosion consisting of hard and/or loose scale, including pitting, over 70% or more of the area under consideration, accompanied by evidence of thickness diminution.


FAF (Fuel Adjustment Factor Fully Found): A vessel completely equipped and manned for service. deck lashing strap dolphin drip pan fish plate


FAIR condition is a term used to describe the condition of a hard coating; with local breakdown at edges of stiffeners and weld connections and/or light rusting over 20% or more of areas under consideration, but less than as defined for POOR condition.

Fair: to smooth or fair up a ship's lines and eliminating irregularities.


Fairing: Re-forming distorted steel to its original form or shape.


Fatigue: The phenomenon leading to fracture under repeated or fluctuating stresses having a maximum value significantly less than the ultimate tensile strength of the material.


FEED: Front-End Engineering and Design – part of a project’s life cycle.


Fleet Boat: A boat that primarily tends, tows within, or otherwise services a fleeting area.


Fleeting Area (Fleeting): A designated portion of a waterway where vessels are regularly moored and tended. The area at which barges, towboats and tugs are berthed until needed. The operation of building or dismantling barge tows.


Flow Meter: A device installed in a pump manifold or treating line to measure the fluid flow rate.


Flush Deck: A deck running from stem without being broken by forecastle or poop.

Flush Deck Ship: A vessel having an upper deck extend continuously from bow to stern.


Fogbound: Immobilized by heavy fog.


Foreign Trade Zone (FTZ) - Known in some countries as a free zone, a foreign trade zone (FTZ) is a site within the USA (in or near a U.S. Customs port of entry) where foreign and domestic goods are held until they ready to be released into international commerce. If the final product is imported into the U.S., duties and taxes are not due until the goods are release into the U.S. market. Merchandise may enter a FTZ without a formal Customs entry or the payment of Customs duties or government excise taxes. In the zone, goods may be: stored; tested; sampled; repackaged or relabeled; cleaned; combined with other products; repaired or assembled, etc.


FOB (Free On Board): An International Term of Sale that means the seller fulfills his or her obligation to deliver when the goods have passed over the ship’s rail at the named port of shipment. This means that the buyer has to bear all costs and risks to loss of or damage to the goods from that point. The FOB term requires the seller to clear the goods for export.


FWPCA (Federal Water Pollution Control Act): the U.S. federal statute that establishes the legal and financial responsibilities of those persons or companies that discharge or dispose of oil or hazardous substances into or upon the navigable waters of the U.S. Primarily administered by the U.S. Coast Guard.


Force Majeure: The title of a common clause in contracts, exempting the parties for non-fulfillment of their obligations as a result of conditions beyond their control, such as earthquakes, floods or war. Any cause or event reasonably beyond the control of a Party, including (but without limiting the generality of such term): act(s) of god, perils of the sea, fire, delay of the performing vessel arising from breakdown or adverse weather, accidents at, closing of, or restrictions upon the use of mooring facilities, docks, ports, pipelines, harbors, railroads, or other navigational or transportation mechanisms, natural disasters (such as violent storms, cyclones, earthquakes, tidal waves, floods, destruction by lightening), war (declared or undeclared), military operations, blockade, revolution, riots, acts of piracy, acts of sabotage, disruption or breakdown of or explosions or accidents to wells, storage plants, refineries, pipelines, terminals, machinery or other facilities, trade restrictions, strike, lockouts, or a dispute or difference with workers, labor shortage requests, good faith compliance with any orders or actions, whether voluntary or involuntary, of any Governmental Authority, or by any Person purporting to represent a government, any reduction in, failure or refusal to deliver supplies of Product or the raw materials or energy used to manufacture such Product from Seller’s sources of supply, whether lawful or otherwise, or any other cause of a similar nature as described herein not reasonably within the control of the respective Parties.


Forging: A mass of metal worked to a special shape by hammering, bending, or pressing while hot.


FOW: First Open Water; also, Free On Wharf


Frame: Vertical structural component supporting and/or stiffening hull side plating and maintaining the transverse form. The ribs of a ship. Frame Head: The section of a frame that rises above the deck line.

Frame Lines: Lines of a vessel as laid out on the mold loft floor, showing the form and position of the frames. Also the line of intersection of shell with heel of frame.

Frame Spacing: The fore-and-aft distances between frames, heel to heel.

Frame Station(s): Points at which transverse frames (or floors) are located, indicated on the baseline, numbered from zero at the aft perpendicular and terminating at or beyond the forward perpendicular. Stations abaft the aft perpendicular are numbered negatively.


Free Time: That amount of time that a carrier’s equipment may be used without incurring additional charges. (See Storage, Demurrage or Per Diem)


Freeboard: The distance from the waterline to the main deck of a boat or barge.


Fracture is the propagation of a crack through the thickness of a material. (See ‘Brittle’ and ‘Ductile’ Fractures)


Front Watch: The watch that starts at 0600 hours and ends at 1200 hours then starts again at 1800 hours and ends at 2400 hours.


Fuel Transfer Diagram: A schematic of the vessel’s fuel system including fueling ports and vents.


Fully Found: A vessel completely equipped and manned for service.


Galvanic Corrosion: Electrochemical accelerated corrosion of a metal because of an electrical contact with a more noble metal or nonmetallic conductor in a corrosive electrolyte.

Galvanizing is the deposition of zinc on to the surface of steel to provide corrosion protection by both protecting the steel from contact with the environment and giving sacrificial protection.


Gallon: A US gallon of 231 cubic inches at 60 degrees Fahrenheit (60°F).


Gas Free: The process of removing all hazardous gases and residues from the compartments of a vessel. Gasket An elastic packing material used for making joints watertight.


Gauge: A waterway marker that measures the level of the water in foot increments; also refers to the specific measure on the gauge.


General Corrosion or Overall Corrosion appears as non-protective, friable rust of a uniform nature on uncoated surfaces. Rust scale continually breaks off, exposing fresh metal to corrosive attack. Visual judgment of thickness loss is difficult until serious wastage has occurred.


GMDSS (Global Maritime Distress Safety System): .The GMDSS is an internationally agreed-upon set of safety procedures, types of equipment, and communication protocols used to increase safety and make it easier to rescue distressed ships, boats and aircraft. GMDSS consists of several systems, some of which are new, but many of which have been in operation for many years. The system is intended to perform the following functions: alerting (including position determination of the unit in distress), search and rescue coordination, locating (homing), maritime safety information broadcasts, general communications, and bridge-to-bridge communications. Specific radio carriage requirements depend upon the ship’s area of operation, rather than its tonnage. The system also provides redundant means of distress alerting, and emergency sources of power.

GOOD condition is a term used to describe condition of hard coating; with only minor spot rusting.


Governmental Authority: Any federal, state, local, foreign government, any provincial, departmental or other political subdivision thereof, or any entity, body or authority exercising executive, legislative, judicial, regulatory, administrative or other governmental functions or any court, department, commission, board, bureau, agency, instrumentality or administrative body of any of the foregoing.


Grain: Unspecified type of grain (may include soybeans, sorghum, corn, wheat, etc.). Heavy Grain: Soybeans, corn, and sorghum.


Grain Export Regions: Pacific Northwest, Mississippi River, Texas Gulf, East Gulf, Great Lakes, and Atlantic.

Great Circle: A course plotted on the surface of the globe that is the shortest distance between two points.


Great Lakes: A grain export region that includes U.S. export elevators in Duluth, MN; Milwaukee and Superior, WI; Chicago, IL; Portage, IN; Huron, Maumee, and Toledo, OH. The region also includes Canadian elevators in Windsor, in the Province of Ontario; and Baie Comeau, Montreal, Port-Cartier, Quebec City, Sorel-Tracey, Trois Riveieres, in the Province of Quebec.

Grooving Corrosion: Local corrosion normally adjacent to welding joints along abutting stiffeners and at stiffener or plate butts or seams.


Gross Tonnage (GT): Applies to vessels, not to cargo. (0.2+0.02 log 10V) where V is the volume in cubic meters of all enclosed spaces on the vessel. The volume measurement of the internal voids of a vessel wherein 100 cubic feet equals one ton.


Ground Tackle: A term used to cover all of the anchor gear.

Grounding: Running ashore (hitting the bottom). Contact of the ship’s bottom with the sea floor.

Groundways: Large pieces of timber laid across the ways on which the keel blocks are placed. Also the large blocks and plans which support the cradle on which a ship is launched.


Hand: A member of the ship’s company


Hand Taut: As tight as can be pulled by hand.


Handy Line / Heaving Line: Small line used to help in mooring operations where the distance is to far to catch a mooring line or cable. (By throwing a handy line to another person then tie the handy line to the mooring line to heave the mooring line to heave the mooring line to the lock, dock, vessel, etc.)


Harbor Boat: Any powered vessel, which is used primarily in harbor operations.


Hard Alee: The command given to inform the crew that the helm is being turned quickly to leeward, turning the boat windward.

Hard Coating is a coating which chemically converts during its curing process, normally used for new construction, or non-convertible air drying coating which may be used for maintenance purposes. Hard coating can be either organic or inorganic and covers typical marine coatings such as those based on epoxy, coal tar epoxy, polyurethane, chlorinated rubber, vinyl, zinc epoxy, zinc silicate.


Hatch: An opening in the top of a tank through which samples are taken or inspection is made.


Head of Navigation: The uppermost limit of navigation from the mouth of a waterway.

Hip Towing: A method of towing whereby the vessel being towed is secured along-side the towboat.


Heavy Oil: Crude oil with an API gravity less than 20°. Heavy oil generally does not flow easily due to its elevated viscosity


Heavy Metal [Drilling Fluids]: A term used by US Environmental Protection Agency (EPA) to specify the elements cadmium (Cd) and mercury (Hg). In a broader sense, the term can be used to specify other metals for which environmental concerns exist, such as copper, lead, chromium, nickel, arsenic and zinc. NPDES permits for offshore drilling set limits on Cd and Hg concentrations in barite that go into drilling fluids to be discharged offshore. Cadmium sulfide and mercury sulfide are minerals associated with barite ores. Maximum concentrations are Cd >= 1 and Hg >= 3 ppm (mg/kg).


Hip Towing. Image credit: Karatzas Images

Hip Towing (Hipping): A method of towing whereby the vessel being towed is secured alongside the towboat. Also, "On The Hip Tow".


Hog: A scrub-broom for scraping a ship’s bottom under water.

Hog Frame: A fore-and-aft frame, forming a truss for the main frames of a vessel, to prevent bending.

Hog Sheer: The curve of the deck on a vessel constructed so that the middle is higher than the ends.

Hogged: A ship that is damaged or strained so that the bottom curves upward in the middle opposite of sagged.

Hogging: A ship is said to hog when the hull is bent concave downwards by the forces acting on it. Hogging is the opposite of sagging.


Home Port: The port city that is the home base of a vessel or the city from which it is documented.


Hook: The high-capacity J-shaped equipment used to hang various other equipment, particularly the swivel and kelly, the elevator bails or topdrive units. The hook is attached to the bottom of the traveling block and provides a way to pick up heavy loads with the traveling block. The hook is either locked (the normal condition) or free to rotate, so that it may be mated or decoupled with items positioned around the rig floor, not limited to a single direction. Hook Load: The total force pulling down on the hook.


Hopper: 1) In general, a funnel-shaped device used to transfer products. The hopper is often at the bottom of any container for holding or using bulk products, especially drilling fluid additives and cementing material. 2. n. [Drilling] The device used to facilitate the addition of drilling fluid additives to the whole mud system. While several types of hoppers exist, they generally have a high velocity stream of mud going through them and a means of mixing either dry or liquid mud additives into the whole mud stream. The resultant mixed mud is then circulated back into the surface mud system. A hopper is generally used to introduce relatively small quantities of additives to the mud system.


Hopper Barge: An open compartment barge used for carrying bulk cargo.


Horizon Glass: On a sextant, the glass or lens through which the horizon is observed. The half of the glass nearer to the sextant frame is a mirror, the other half is clear.


Horning: Setting the frames of a vessel square to the keel after the proper inclination to the vertical due to the declivity of the keel has been given. Horse latitudes: The latitudes on the outer margins of the trades where the prevailing winds are light and variable.


Horsepower: A standard unit of power that is often classified in connection with engines as brake, continuous input, intermittent, output, or shaft horsepower.


Hose Testing: Carried out to demonstrate the tightness of structures not subject to structural (hydrostatic) or leak testing and to other components that contribute to the watertight or weathertight integrity of the hull.


Hot Oil Barge: A barge equipped with a system that consists of a boiler, which burns fuel oil and fires a burner which transmits heat to the special oil circulated through heating coils. This system is used to maintain the minimum temperature of certain heavy petroleum products.

Hydropneumatic Testing: A combination of hydrostatic and air testing.


IACS: International Association of Classification Societies


ICC (Interstate Commerce Commission): a U.S. governmental agency that regulates the domestic transportation of certain commodities.


IGS: Inert Gas System.


Illinois River Lock 8 (Located in Versailles, IL at mile 80 on the Illinois River): This is a single chamber lock that is 600 ft by 110 ft in dimension (also called LaGrange Lock).


In Bond: Cargo moving under Customs control where duty has not yet been paid.

Indent is deformation of structural members caused by out of-plane loads like bottom slamming and bow impact forces, contact with other objects etc.

Inhibitors are substances used to prevent or retard a chemical or electrochemical reaction, often used to render corrosion products less soluble and thereby tending to stifle electrochemical corrosion processes.


Inland Waters: Considered to be the canals, lakes, rivers and their tributaries, and bays and sounds of the land mass of a country.


Insignificant Corrosion or Minor Corrosion is an extent of corrosion with minor spot rusting and such that an assessment of the corrosion pattern indicates wastage generally not exceeding of 30% of the allowable corrosion limits.

Inspection Port: A watertight covering usually small, that may be removed so the interior of the hull can be inspected or water removed.


Insurance, All-Risk: This type of insurance offers the shipper the broadest coverage available, covering against all losses that may occur in transit.


Insurance, General-Average: In water transportation, the deliberate sacrifice of cargo to make the vessel safe for the remaining cargo. Those sharing in the spared cargo proportionately cover the loss.


Integrated Tow: A tow of box-ended barges that, as a complete unit, is raked at the bow, boxed at the intermediate connections, and boxed or raked at the stern.


Intercoastal: Water service between two coasts; in the U.S., this usually refers to water service between the Atlantic and Pacific or Gulf Coasts. The system of inland waterway channels running along the Atlantic and Gulf coasts of the United States from Manasquan inlet, New Jersey, to the Mexican border in Texas; commonly abbreviated as ICW. GIWW: Gulf Intracoastal Waterway.


Intermodal Shipment: When more than one mode of transporation is used to ship cargo from origin to destination, it is called intermodal transportation. For example, boxes of hot sauce from Louisiana are stuffed into metal boxes called containers at the factory. That container is put onto a truck chassis (or a railroad flat car) and moved to a port. There the container is lifted off the vehicle and lifted onto a ship. At the receiving port, the process is reversed. Intermodal transportation uses few laborers and speeds up the delivery time.


ISPS Code: The International Code for Security of Ships and Port Facilities, as set forth in Title 33, CFR Chapter I (Subchapter H) and relevant amendments to Chapter XI-2 of the International Convention for the Safety of Life at Sea, 1974 (SOLAS), as such may be amended from time to time.


Jack Staff: A vertical pole erected on the lead barge of a tow used by the pilot for aligning the heading of the tow, also used as a swing indicator.


Jones Act: The term refers to several U.S. laws that govern the domestic transportation of merchandise and passengers by water. Strictly speaking, it applies only to Section 27 of the Merchant Marine of 1920 [46 U.S.C. 883; 19 CFR 4.80 and 4.80(b)] which has come to bear the name of its sponsor, Senator Wesley L. Jones. Section 27 provides that merchandise transported entirely or partly by water between U.S. points—either directly or via a foreign point—must travel in U.S.-built, U.S.-citizen owned and operated U.S.-flag vessels that are U.S.-documented by the Coast Guard for such carriage.

Jocky Wire: Wire used to keep barges coupled end on end from moving sideways. John Boat: A small (usually with an outboard motor) skiff-type boat used for various reasons such as crew change in shallow water or while underway, mooring etc. Also, see Skiff Boat: A small boat carried aboard a towboat, also called Yawl.


Jackup Rig: A self-contained combination drilling rig and floating barge, fitted with long support legs that can be raised or lowered independently of each other. Offshore exploration and development wells are often drilled from mobile offshore drilling units (MODUs, pronounced "moe-dooz"). Depending on the water depth and remoteness of the location, these "rigs" may be jack-ups (up to 400 feet of water), or semi-submersibles, or drillships (up to 12,000 feet of water). Jack-ups are bottom-supported units; semi-submersibles and drillships are floating units ("floaters"). In terms of numbers, jack-up rigs drill most offshore wells. Semi-submersibles run a distant second, and drillships come in third, though most of the major new discoveries today are being made by the floaters in deep and ultra-deep water. Oil companies ("operators") select rigs that are specifically suited for a particular job, because each rig and each well has its own specifications and the rig must be matched to the well. The jackup, as it is known informally, is towed onto location with its legs up and the barge section floating on the water. Upon arrival at the drilling location, the legs are jacked down onto the seafloor, preloaded to securely drive them into the seabottom, and then all three legs are jacked further down. Since the legs have been preloaded and will not penetrate the seafloor further, this jacking down of the legs has the effect of raising the jacking mechanism, which is attached to the barge and drilling package. In this manner, the entire barge and drilling structure are slowly raised above the water to a predetermined height above the water, so that wave, tidal and current loading acts only on the relatively small legs and not the bulky barge and drilling package.


Keel Line: An imaginary line describing the lowest portion of a vessel’s hull.


Kilogram per cubic meter: The SI unit of measurement for density. Mud weights are typically expressed in kg/m3. The conversion factor from lbm/gal to kg/m3 is 120. For example, 12 lbm/gal = 1440 kg/m3.


Knot: One nautical mile (6,076 feet or 1852 meters) per hour. In the days of sail, speed was measured by tossing overboard a log which was secured by a line. Knots were tied into the line at intervals of approximately six feet. The number of knots measured was then compared against time required to travel the distance of 1000 knots in the line.


KPI: Key Performance Indicator

Labor: A vessel is said to labor when she works heavily in a seaway (pounding, panting, hogging and sagging).


Laden: Loaded aboard a vessel.


Lamination: An excessively large, laminar, non-metallic inclusion, producing a defect appearing in sheets or strips as segregation or in layers.

Landfall: A sighting of or coming to land, also the land so approached or reached; the land first sighted at the end of a sea voyage.


Landing: An improved waterfront property that facilitates loading, unloading, and servicing of vessels.


LaGrange Lock (Located in Versailles, IL, at mile 80 on the Illinois River): This is a 600 ft by 110 ft single lock chamber (also called Illinois River Lock 8). Landed Cost: The farm value of a commodity plus the cost of transportation from the farm to the final destination point. The transportation cost includes trucking, rail, barge, and ocean freight rates.


Lap Joint: A joint between two structural members that overlap each other.

Latitude: An angular measurement or distance measured in degrees, north or south from the equator which is 0.


LAYCAN: Laydays / Cancelling (date): Range of dates within which the hire contract must start.


LCL: The acronym for "less than container load." It refers to a partial container load that is usually consolidated with other goods to fill a container.


Lead Barge: The head or first barge of a tow.


Leak Testing: An air or other medium test carried out to demonstrate the tightness of the structure.

Lee: The side away from the direction of the wind, also used in context to refer to a sheltered place out of the wind, as in the lee of the island.

Leeward: Downwind or away from the wind.


Life Cycle Analysis (LCA): LCA is an analytical methodology used to comprehensively quantify and interpret the environmental flows to and from the environment (including air emissions, water effluents, solid waste and the consumption/depletion of energy and other resources) over the life cycle of a product or process. LCAs should be performed in adherence to the International Organization for Standardization (ISO) 14040 series of standards.

Lifeline: A cable fence that surrounds the deck to assist in the prevention of crew falling overboard. Safety lines and guardrails rigged around a boat's deck to prevent the crew from being washed overboard.


Liftboat: A liftboat is a self-propelled, multi-purpose, self-elevating vessel. Some have referred to liftboats as jack-up barges, lift barges, jack-boats. We will examine the distinguishing features of a liftboat as compared to its closest cousin, the jack-up drilling rig. Since, a liftboat spends most of its working life out of the water, it is felt it better to address what it does during its working life.


Light Boat: A towboat without a barge in tow.


Lightening Hole: A hole cut in a plate or frame to reduce its weight without reducing its strength.


Light Screen: A structure surrounding a vessel’s navigation light so as to shield the light from view at certain points of the compass as required by navigational regulations.


Lighter: A vessel, usually a barge, that is used in loading or unloading a ship or in transporting cargo in and around a harbor.


Lights (Navigation Lights): Those lights aboard a vessel or a tow required to be shown at night and at other times of restricted visibility.


Lights (Towing Lights): Two amber lights, one atop the other displayed at the stern of a towboat.


Lights (Running Lights): Lights required to be shown at night aboard a vessel or a tow while underway.


Line of Position: A straight line somewhere along which a ship is presumed to be. The line may be determined either by ranges, or by visual or electronic bearings.


Limber Hole: A drain hole near the bottom of a frame or bulkhead.


Lines: The ropes or cables used on a vessel for towing, mooring or lashing.

List: The leaning of a boat due to excess weight on one side or the other.


Loadline Marks: A set of permanent markings on the side of an oceangoing or Great Lakes vessels which denotes its maximum legal operating draft under certain specified conditions and which is determined by one of the internationally recognized assigning agencies.


Local Corrosion is by name local in nature, often appearing at areas with local breakdown of coating or at areas with stress concentrations.

Lock: An enclosure on a river or canal, with movable, watertight gates, through which vessels pass, and proceed from one water level to another by raising or lowering the water within the lock chamber. A structure on the river that facilitates the transfer of vessels from one water level to another water level. There are two lock configurations - a single lock or a double lock. The latter can be defined as the main lock and an auxiliary lock.


Lock (Main): The larger chamber of a double lock that transfers vessels from one water level to another water level. The advantage of this double lock facility is that both chambers can be working at the same time, and more importantly, while one chamber is closed for repairs, the other chamber can handle the traffic. See Auxiliary Lock Chamber.


Lock Gate: A movable, structural barrier to hold back the water in a lock chamber.


Lockmaster: Person employed by Corps of Engineers who is in charge of ensuring safe passage of vessels through locks.


Loftsman: A man who lays out the ship’s lines in the mold loft and makes the molds or templates therefrom.


Log Book or Logbook (Logs): The official records of the daily operations of a manned vessel, kept in detail by the master.: A continuous operating record of a ship kept by one of its officers. In it are recorded daily all important events occurring on board, also the condition of the weather, the ship’s position and other data.


Log: A device for measuring the rate of a ship's motion through the water; also, a ship's journal or written record of the vessel's day-by-day performance, listing speeds, distances travelled, weather conditions, landfalls and other information.


Loll: A ship which is slightly unstable in the vertical position will heel until the GZ curve becomes zero. It is said to loll and the angle it takes up is the angle of loll.


Long Ton: A measure of weight equal to 2,240 pounds or 1,016 kilograms; used to measure petroleum products. See also metric ton and short ton.


Longitude: Distance in degrees east or west of Greenwich, England, meridian which is 0.


Longitudinal Center of Buoyancy (LCB): The fore and aft location of the center of buoyancy. Longitudinal Center of Gravity (LCG): The fore and aft location of the center of gravity. Longitudinal Stability: The stability of a ship for rotation (trim) about a transverse axis.

Loose Scale: Sheets of rust falling off if the surveyor hits the structure with his test hammer. Loose scale can best be removed by hand or power tool cleaning or a combination of these.

Loran: A radio positioning system that allows navigators to make position fixes by the reception of synchronized low-frequency radio transmissions. The word loran is an acronym for long-range navigation.


Lyle Gun: A gun used in the life-saving services to throw a life line to a ship in distress or from ship to shore and used when a boat cannot be launched.


MAIB: Marine Accident Investigation Branch


Make-Up: The act of final positioning and securing of the vessels that form a tow.


Maltese Cross A-1: The designation used by ABS which signifies that a vessel has met the classification requirements of that agency.


Manhole: A framed opening in the deck of a vessel which primarily provides access for a man. A hole in a tank, boiler or compartment on a ship, designed to allow the entrance of a man for examination, cleaning and repairs.


Manhole Cover: A cover which seals a manhole and is usually designed to lock in place by twisting or using a centerbolt, studbolts, or dogs.


Manifest: The ship captain’s list of individual goods that make up the ship’s cargo.


MARAD: The U.S. Maritime Administration.


Marine Chemist: One who is certified to perform inspections in accordance with the Standard for the Control of Gas Hazards on vessels to be repaired as adopted by the National Fire Protection Association.


Marine Chemist’s Certificate: The documentation of a vessel’s inspection by a marine chemist and his assignment of standard safety designations to the inspected compartments or spaces.


Marine Claim: Any dispute or claim arising under these Marine Provisions, including a demurrage claim dispute.


Marine Incident: Usually defined as any incident or event outside normal Vessel operation that delays the Vessel for a period of three (3) or more hours, including spills, personal injury, fire, grounding, collision, security issue, vessel seizure, or significant media or governmental inquiry.


Marine Surveyor (Surveyor): Person who inspects a ship hull or its cargo for damage or quality.


Maritime Security Regulations: Collectively, the ISPS Code and the MTSA, if and when such are applicable.


Master: The officer in charge of the ship. "Captain" is a courtesy title often given to a master. The person who has complete charge of and authority aboard an operating vessel.


Mats: Slabs, usually constructed of timbers, which are placed on the deck of a vessel for the purpose of supporting and distributing the weight of heavy loads.


Maximum Allowable Working Pressure ((MAWP): A design standard which represents the highest pressure a piece of equipment should be exposed to.


Mean High Water (MHW): The average level of high tide for any area. Highest average level water reaches on an outgoing tide.

Mean Low Water (MLW): The average level of low tide for any area. Lowest average level water reaches on an outgoing tide.


Melvin Price Locks (Alton, IL at mile 201 on the Upper Mississippi River): This double lock has a 1,200 ft. by 110 ft. main lock chamber and a 600 ft. by 110 ft. auxiliary lock (also called Mississippi River Lock 26).


Metacenter: The intersection of successive vertical lines through the center of buoyancy as a ship is heeled progressively. For small inclinations the metacenter is on the centerline of the ship. Metacentric Diagram: A plot showing how the metacenter and center of buoyancy change as draught increases. Metacentric Height (GM): The vertical separation of the metacenter and the center of gravity as projected on to a transverse plane.


Metric Ton: A measure of weight equal to 2,204.6 pounds or 1,000 kilograms. There are 39.3 bushels of corn per metric ton, and 36.7 bushels of soybeans or wheat per metric ton. See also long ton and short ton.


Middle Body: The part of a ship adjacent to the midship section. When it has a uniform cross section throughout its length, with its water lines parallel to the center line, it is called the parallel middle body.

Midship: The middle of the vessel.

Midship Area Coefficient (CM): One of the coefficients of fineness. It is the ratio of the underwater area of the midship section to that of the circumscribing rectangle.


Milemarker (Mileboard): A marker set up to indicate distances in miles along a waterway.


Mill Scale is thick oxide film formed on wrought-metal products which have been hot- rolled or forged and allowed to cool in air, the term is principally applied to steel on which the oxide is essentially magnetic black oxide.


Mississippi River: A grain export region that includes export elevators along the Mississippi River at Ama, Belle Chasse, Convent, Darrow, Destrehan, Paulina, Port Allen, Reserve, and Westwego, LA. Mississippi River Lock 25 (Located in Winfield, MO., at mile 242 on the Upper Mississippi River): This lock is a 600 ft. by 110 ft. single lock chamber. Mississippi River Lock 26 (Alton, IL. at mile 201 on the Upper Mississippi River): This is a double lock with a 1,200 ft. by 110 ft. main lock chamber and a 600 ft. by 110 ft. auxiliary (also called Melvin Price Locks).

Mississippi River Lock 27 (Located in Granite City, IL. at mile 186 on the Upper Mississippi River): This is a double lock with a 1,200 ft. by 110 ft. main lock chamber and a 600 ft. by 110 ft. auxiliary (also called Chain of Rocks Locks). Mississippi River Locks 15 (Located in Rock Island, IL. at mile 482 on the Upper Mississippi River): This is a double lock with a 600 ft. by 110 ft. main lock chamber and a 360 ft. by 110 ft. auxiliary lock chamber.


Model Hull: A type of hull design in which the form is molded, curved, and shaped into a pointed and rounded stem.


Model Bow Boats: Boats with the pointed bows (as compared to boats with squared bows, such as push boats).  Tug boats are generally either model bow tugs or push boats. Model bow tugs can be used in both inland and offshore waters, and can have shallow draft or very deep draft, and can be used as either push boats or pull boats. 


MODU (Mobile Offshore Drilling Unit): A generic term for several classes of self-contained floatable or floating drilling machines such as jackups, semisubmersibles, and submersibles.


Molded Depth: The distance from the top of the keel to the top of the upper-deck beams amidships at the gunwale.


Moon Pool: The opening in the hull of a drillship or other offshore drilling vessel through which drilling equipment passes.


MRGO (Mississippi River Gulf Outlet): Waterway connecting the New Orleans Inner Harbor Navigation Canal to the Gulf of Mexico.


MTSA: The US Maritime Transportation Security Act of 2002, as codified under 46 US Code, Chapter 701, as such may be amended from time to time.


NAMS: National Association of Marine Surveyors.


Natural Gas Liquids (NGLs): A general term for highly volatile liquid products separated from natural gas in a gas processing plant. NGLs include ethane, propane, butane and condensate.


Navigable Pass: he water pass through which vessels may pass over a movable dam during periods of high water. The wickets of the dam are lowered to the river bend and the water flows with little or no obstruction. Passes are usually from 600' to 900' in width when the dam is lowered. These are usually found in the Ohio and Illinois River. Navigable Waters: Those waterways upon which commercial or private vessels are able to operate in their customary mode of navigation.


Navigation Lights: Those lights aboard a vessel or a tow required to be shown at night and at other times of restricted visibility.


Neap Tide: A tide of less than average range, occurring at the first and third quarters of the moon.


Nipple: Any short piece of pipe, especially if threaded at both ends with male threads.


NOR: Notice of Readiness.


Norrell Loc (Located in Tichnor, AR., at mile 10 on the Arkansas River): This lock is a 600 ft. by 110 ft. single lock chamber (also called Arkansas River Lock and Dam 1).


NVOCC: A non-vessel-owning common carrier that buys space aboard a ship to get a lower volume rate. An NVOCC then sells that space to various small shippers, consolidates their freight, issues bills of lading and books space aboard a ship.


OCIMF: The Oil Companies International Marine Forum.


OCMI (Officer in Charge of Marine Inspections): A U.S. Coast Guard Marine Inspection office. Such offices are located in a number of U.S. ports.


Official Number: The registration number assigned by the U.S. Coast Guard to a U.S. documented vessel, which is permanently marked on the main beam of that vessel.


Offshore: Waters A common term for those waters that are beyond inland water limits and have the technical classification of oceans.


Ohio River Locks 5 (Located in Brookport, IL. at mile 939 on the Ohio River): This is a double lock with a 1,200 ft. by 110 ft. main lock chamber and a 600 ft. by 110 ft. auxiliary chamber.


Omni: A navigation system that provides bearings by means of a VHF radio signal: also known as visual omni range (VOR). The system was originally designed for aviators, but it's also used by mariners.


On The Hip / Hip Towing: Barge towed alongside the boat. Also, Hip Towing (Hipping).


OPA: The (US) Oil Pollution Act of 1990, as such may be amended from time to time.


Optimum Fuel Burn: Best balance between vessel speed and fuel consumption.


Owner Code (SCAC) Standard Carrier Abbreviation Code: identifying an individual common carrier. A three letter carrier code followed by a suffix identifies the carrier’s equipment. A suffix of “U” is a container and “C” is a chassis.


NAABSA: Not Always Afloat But Safely Aground

Nantucket Sleigh Ride: A term for what frequently happened to Nantucket whalers when they left the whaling ship in a small boat to go after a whale. If they harpooned the whale without mortally wounding it, the animal took off with the whaleboat in tow.


Nautical Mile: A unit of length used in sea navigation equal to 1852 meters or approximately 6076 feet. Measure of length at sea (2025 yards). 1 mile = 1,760 yards.


Navigable Waters: Those waterways upon which commercial or private vessels are able to operate in their customary mode of navigation.


Necking Effect: Term describing local corrosion at junction of plating and stiffeners due to flexure effects caused by reverse, cyclic loading with loss of coating or shedding of scale exposing fresh steel to further corrosion. The corrosion rate may be rather high and accelerates with thinning of the material.


Net Tonnage (NT): (0.2+0.02 log 10(Vc)) Vc (4d/3D)2, for passenger ships the following formula is added: 1.25 (GT + 10000)/10000 (N1 + (N2/10)), where Vc is the volume of cargo holds, D is the distance between ship’s bottom and the uppermost deck, d is the draught N1 is the number of cabin passengers, and N2 is the number of deck passengers.) “Ton” is figured as a 100 cubic foot ton.


Net Tons: The gross tons of a vessel, less deductions for certain specified non-cargo spaces, resulting in a net volume capacity of 100 cubic feet per ton. (See gross tons)


On-hire / Off-hire Survey: Surveys carried out to state the ship's condition prior to or after her chartering. The main purpose is to record deficiencies or damages.


Out of Trim: Not properly trimmed or ballasted (not on even keel; listing).

Outboard: In a direction towards the side of the ship. Away from the keel or center of a vessel on either side.

Outboard Profile: A plan representing the longitudinal exterior of a vessel, showing the starboard side of the shell, all deck erections, masts, yards, rigging, rails, etc.

Overall Survey: Survey intended to report on the overall condition of the hull structure and determine the extent of additional close-up surveys.


P&I Insurance: Protection and Indemnity Insurance.

Paint can be described as a liquid material capable of being applied or spread over a solid surface on which it subsequently dries or hardens to form a continuous adherent, obliterating film.

Paint Cracking: Deep cracks in paint that expose substrate.

Periodical Survey: A collective term of classification surveys carried out after the delivery a ship and at prescribed time intervals, i.e. annual, intermediate and renewal/special surveys.


Pilot: A licensed navigational guide with thorough knowledge of a particular section of a waterway whose occupation is to steep ships along a coast or into and out of a harbor. Local pilots board the ship to advise the captain and navigator of local navigation conditions (difficult currents; hidden wrecks, etc.).

Pinholing is tiny, deep holes exposing substrate.

Pinpoint Rusting: Local rusting at pinholes or holidays.


Pipelaying Vessel: Pipelaying vessel (PLV) or pipelay vessel is a specialized floating facility for submerged pipeline laying. It is widely used in offshore fields development for laying pipelines up to 1,420 millimeters in diameter down to 2,500 meters depth. Submerged pipelines can be constructed on pipelaying vessels by stovepipe welding of pipe sections stored on the deck or by the reel method by which the pipeline produced onshore is wound onto reels beforehand. Winding onto the reel is possible for up to 90 kilometers of 100 to 400 millimeters diameter pipes. During pipeline laying the reel constantly rotates and the pipe is laid down to a 300 meter depth at a speed of up to 4 kilometers per hour. During lowering of the pipeline prepared on a deck a special device (a stinger) supports it to prevent from major bends when moving it from the vessel. The maintenance of all pipelaying vessel systems and welding equipment is performed by a computer (sea depth, wave and wind speeds are taken into account; pipelaying vessel stability is ensured).


Pitch: A tar substance obtained from the pine tree and used in paying the seams of a vessel. Motion of vessel.

Pitching: The oscillatory vertical motion of a vessel forward and aft in a seaway.

Pitguard Anode: A sacrificial anode placed just above tank bottom in order to mitigate the general and pitting corrosion process.

Pitting Corrosion: Local, random scattered corrosion mainly on horizontal surfaces and at structural details where water is trapped, particularly at bottom of tanks. For coated areas the attack produces deep and small diameter pits which may lead to perforation. Pitting of uncoated areas in tanks, as it progresses, forms shallow but very wide scabby patches (e.g. 300 mm in diameter) and the appearance resembles condition of general corrosion.

Plasticity is the property of a material that allows it to be extensively repeatedly deformed without rupture when acted upon by a force sufficient to cause deformation and that allows it to retain its deformed shape after the applied force has been removed.


Platform Supply Vessel (PSV): Platform Supply Vessels (PSV) specially designed to provide transportation and logistics support for the supplies and equipment used on oil and gas production platforms, offshore drilling rigs and other types of offshore vessels and installations. Modern PSVs now incorporate Dynamic Positioning systems as standard, have substantial available deck areas, and the capability underdeck to transport and discharge offshore, oil and water-based muds, brine, fuel, dry bulk cargoes, drill water and potable water.


Plimsoll Mark: The primary loadline mark, which is a circle intersected by a horizontal line, accompanied by letters indicating the authority under which the loadline is assigned.


Plunging: A ship is said to plunge when it sinks bow or stern first through loss of longitudinal stability.


PNW (Pacific Northwest): A grain export region that includes Portland, OR; Kalama, Seattle Tacoma, and Vancouver, WA; Stockton and West Sacramento, CA.


POOR condition is a term used to describe condition of hard coating; with general breakdown of coating over 20% or more or hard scale at 10% or more of areas under consideration.


Port: The left-hand side of a vessel when facing forward; a city having a harbor for vessels; a port hole.


Port (Inspection Port): A watertight covering usually small, that may be removed so the interior of the hull can be inspected or water removed.


Port (Landlord Port): At a landlord port, the port authority builds the wharves, which it then rents or leases to a terminal operator (usually a stevedoring company). The operator invests in cargo-handling equipment (forklifts, cranes, etc), hires longshore laborers to operate such lift machinery and negotiates contracts with ocean carriers (steamship services) to handle the unloading and loading of ship cargoes. (See also: operating port.)


Port (Operating Port): At an operational port like Charleston, South Carolina, the port authority builds the wharves, owns the cranes and cargo-handling equipment and hires the labor to move cargo in the sheds and yards. A stevedore hires longshore labor to lift cargo between the ship and the dock, where the port’s laborers pick it up and bring it to the storage site. (See landlord port.)


Port of Registry (also, Home Port): Port in the country under whose flag a vessel is legally registered


Port State Control (PSC): The examination of vessels for compliance with IMO Conventions and resolutions by state authorities.


PMU: Portable Measuring Unit.


PPE: Personal Protective Equipment

Pratique (also, Free Pratique): A permit by the port doctor for an incoming vessel, being clear of contagious disease, to have the liberty of the port. License or permission to use a port


Privileged Vessel: The ship with the right of way.


Product (in tanker trade): The refined petroleum product, crude oil, condensate, LPG, feedstock, chemical, ethanol, renewable fuel.


Products Tanker: Tanker vessel for the transport of petroleum-based chemicals and refined oil (various grades). Their cargo tanks are coated with epoxy to protect the cargo and also helps in tank cleaning.


Project Cargo: The materials and equipment to assemble a special project overseas, such as a factory or highway.

Prompt and Thorough Repair: Permanent repair completed at the time of the survey to the satisfaction of the surveyor, therein removing the need for imposition of any associated condition of class.


Purge: Introducing Nitrogen to reduce Oxygen levels to a specified percentage. See also Inert.

Pushboat: A highly maneuverable, inland waters, shallow draft towboat, usually designed with a square bow and towing knees, which facilitate its primary method of towing, which is pushing.


QHSE: Quality, Health, Safety & Environment


Quartering Sea: A sea on the quarter (coming from a side of the stern)


Rake: The forward pitch of the stem. The backwark slope of the stern.

Raw Water: The water supply pumped into a boat from the body of water in which it is floating, used for engine cooling, toilet flushing, etc.


Reasonable Certainty: A high degree of certainty. Much more likely to be achieved than not.

Registered: Pertaining to certain vessel data calculated under specific rules and officially documented such as registered length.


Reserve Buoyancy: Watertight volume of a vessel above the waterline.

Responsible Carrier Program (RCP): A vessel safety management program developed by the maritime industry through the American Waterways Operators (AWO) and designed as a framework for continuously improving the industry’s safety performance. AWO members use the RCP as a guide in developing company-specific safety and environmental programs that are tailored to the unique operational environments found in the barge and towing industry. The program supports government regulations, requiring company safety and maintenance standards that are required by federal law or regulation.


Rheology: Generally, the study of how matter deforms and flows, including its elasticity, plasticity and viscosity. In geology, rheology is particularly important in studies of moving ice, water, salt and magma, as well as in studies of deforming rocks.

Rhumb Line: The path a boat follows when sailing toward a specific point on the compass; on a Mercator chart, a straight line.


River Stage: Height of the water at a certain location on a given day.

Ro / Ro: A shortening of the term, “Roll on/Roll Off.” A method of ocean cargo service using a vessel with ramps which allows wheeled vehicles to be loaded and discharged without cranes.


Rock Dumping Vessels: Rock dumping vessels transport and dump rocks of various sizes for offshore and coastal protection applications. The dumping can be done with a large crane, but also through the concepts of side stone dumping vessels and flexible fallpipe vessels.

Rubber-Tired Gantry (RTG): Traveling crane used for the movement and positioning of containers in a container field. RTG's may also be used for loading and unloading containers from rail cars.

Rules of the Road: A code governing vessels as to the lights to be carried, the signals to be made, and their safe and proper navigation in order to avoid collisions. Statutes of the United States provide varying regulations for two areas of navigation. These regulations are known as Inland Navigation Rules and International Navigation Rules.


Running Lights: Lights required to be shown at night aboard a vessel or a tow while underway.

Rust: A visible corrosion product consisting of hydrated oxides of iron and is formed on steel surfaces exposed to moist atmospheric conditions.


Rustbucket: Sailors’ term for an old ship that needed a lot of paint and repairs.


Sacrificial Anode: Anode of zinc attached to the immersed parts of a hull to prevent deterioration of the hull steel through electrochemical reaction. Safety of Life at Sea (SOLAS): A statutory regulation of IMO dealing with the safety of life at sea.

Sagged: Said of a ship which has been strained so that the bottom drops lower in the middle than it is at stem and stern. Opposite of hogged.

Sagging: A ship is said to sag if the forces acting on it make it bend longitudinally concave up. Sagging is the opposite of hogging.

Sags: Excess flow of paint, also called runs or curtains.


Sailing Line: The preferred course for safe and efficient navigation in the channel of a waterway.


SART (Search And Rescue Transponder): A SART is a self-contained, waterproof radar transponder intended for emergency use at sea. The radar-SART is used to locate a survival craft or distressed vessel by creating a series of dots on a rescuing ship’s radar display. A SART will only respond to a 9 GHz X-band (3 cm wavelength) radar. It will not be seen on S-band (10 cm) or other radar.


SBM: Single Buoy Mooring.

Scale: Surface oxidation, consisting of partially adherent layers of corrosion products, left on metals by heating or casting in air or in other oxidizing atmospheres and is the product of the corrosion process of steel with a porous surface layer or flakes, in volume greater than the metal from which it was formed.

Scantlings: The dimensions of a ship's structural members as girders, stiffeners and plates

Scupper: A drainage opening cut flush with the deck of a vessel through the bulwark or bin wall.


Sea Dog: An old sailor.

Sea-going: Capable of going to sea.

Sea Lawyer: A seaman who is prone to argue, especially against recognized authority (big mouth).

Seam: A joint between two structural members lying in the same plane. Typically a seam is used to describe the welded connection of two plates in the longitudinal direction.

Seaworthiness: The fitness of a vessel for its intended use.

Seaworthy: The reasonably staunch, sound, and fit condition describing a vessel’s capability to safely carry its cargo and complete its intended voyage.


Seismic Vessel: Seismic vessels are ships that are solely used for the purpose of seismic survey in the high seas and oceans. A seismic vessel is used as a survey vessel for the purpose of pinpointing and locating the best possible area for oil drilling in the middle of the oceans. Companies engaged in the oil drilling process make use of such vessels so that they find the best possible subsea areas to drill oil. Another major reason such seismic vessels are so important is that if oil drillers do not get the best subsea location to drill the oil and gas, then it could lead to dangerous and threatening consequences for the marine eco-system. The usage of the seismologic vessels prevents such inadvertent mistakes.

Semi-hard Coating: Coating that dries or converts in such a way that it stays flexible although hard enough to touch and walk upon.

Semi-integrated Barge: A barge that is raked at one end and boxed at the other end.


Set Bolt: A bolt used as a drift to force another bolt out of its hole.

Set Iron: Bar of soft iron used on the bending slab to bend frames to the desired shapes. Set the Course: To give the steersman the desired course to be steered.

Shackle: A U-shaped metal fitting used as a connection for line, cable, or chain and which has a pin secured through its end by a nut, cotterpin, or screw threads.


Shake a Leg: An order to make haste

Sheddage: Regardless of the length of stay, a vessel is charged a one-time fee for use of shed space and/or marginal (waterside) rail track space. The charge is based on the length of a vessel.

Sheer: The upward curvature or angle of a vessel’s deck at the bow or stern.

SHEX: Sunday and Holidays Excluded.

SHINC: Sunday and Holidays Included.

Shifting: The short movement or transfer of a vessel within a harbor or mooring area.

Shipper: The person or company who is usually the supplier or owner of commodities shipped. The supplier or owner of commodities named in a contract as the one from whom the goods have been received for shipment. Also called Consignor.

Shop Primer: A rust preventing paint for temporary protection of steel immediately after blasting for protection of the material surface from corrosion during construction and until the final paint system is applied.


Shore Facilities: Any refinery, terminal, storage, or port facility taking deliveries of the Cargo from, or making deliveries of the Cargo to, a Vessel.


Short Ton: A measure of weight equal to 2,000 pounds, or 907 kilograms used in to measure barge capacity. The tonnage figures provided throughout the U.S. Army Corps of Engineers Waterborne Commerce of the United States, WCUS, Parts 1-5 represent short tons. See also long ton and metric ton.


Side Light: Colored light in the forward part of a vessel showing from right ahead to 22 1/2 degrees abaft the beam on each side. The port sidelight is red, the starboard is green. Tows also carry sidelights on the lead barges.


Single Lock: A lock that only has one transfer chamber for vessel or vessels from one water level to another water level.


Skiff Boat: A small boat carried aboard a towboat, also called Yawl. Also, see John Boat.


Slack: The part of a rope hanging loose; the opposite of taut.

Slack Water: The condition of the tide when there is no horizontal motion.

Slamming: The impact of the hull, usually the bow area, with the sea surface when in waves.


Social Life Cycle Analysis (S-LCA): A methodology for assessing internalities and externalities of the production of goods and services based on social and socioeconomic indicators.


SOF: Statement of Facts.

Soft Coating: Coating that remains soft so that it wears off at low mechanical impact or when touched; often based on oils (vegetable or petroleum) or lanolin (sheep wool grease). Application of soft coating does generally not allow relaxation of the extent of periodical hull survey requirements of ballast tanks.

SOPEP (Shipboard Oil Pollution Emergency Plan): a U.S.C.G. approved set of guidelines for responding to a spill or potential spill of oil from any vessels engaged in international voyages, with certain exceptions, as mandated in Regulation 26 of Annex I of the International Convention for the Prevention of Pollution from Ships, 1973, as modified by the Protocol of 1978 (MARPOL 73/78).


SPM: Single Point Mooring.


Spot Chartered Equipment: When the owner of the Vessel places the Vessel and its crew at the disposal of the Charterer for a single voyage, with such owner being responsible for the operation of the Vessel.


Stability: Tendency of the ship to remain upright. It is paramount that a vessel is stable in all respects at all times. When cargo is loaded / discharged, the stability is monitored by a computer, which takes into account the weight and position of cargo within the vessel.


Standard Industrial Classification (SIC): A standard numerical code used by the U.S. Government to classify products and services.

Starboard: The right-hand side of a vessel when facing forward.


Static Load: Structural loading of constant magnitude and application.

Statutory Survey: A collective term of surveys required to meet International

Convention requirements such as Load Line, SOLAS and MARPOL.

Steamship: Today, ships that transport cargo overseas are powered by diesel fuel instead of steam. Many people still use the term "steamship," but the more modern term for the service is "ocean carrier" and for the ship itself, "motor vessel."

Steamship Agent: The local representative who acts as a liaison among ship owners, local port authorities, terminals and supply/service companies. An agent handles all details for getting the ship into port; having it unloaded and loaded; inspected and out to sea quickly. An agent arranges for pilots; tug services; stevedores; inspections, etc., as well as, seeing that a ship is supplied with food, water, mail, medical services, etc. A steamship agency does not own the ship.

Steamship Company: A business that owns ships that operate in international trade.

Steamship Line: A steamship (ocean carrier) service running on a particular international route. Examples: NSCSA (National Shipping Company of Saudi Arabia), American President Lines (APL), Maersk Sealand, Evergreen, etc.

Stern: The after or rear end of a vessel.

Stevedores: Labor management companies that provide equipment and hire workers to transfer cargo between ships and docks. Stevedore companies may also serve as terminal operators. The laborers hired by the stevedoring firms are called stevedores or longshoremen.

Strain: Any forced change in the dimensions of a structural member.

Strapping Table: A chart used to convert readings of liquid levels in the tanks of a barge to volume measurements of that liquid.

Stress Concentration or Stress Raiser: A term used of any notch, crack, hole, corner, groove, attachment or other interruption to smooth flow of stress and strain in structures introduces a concentration of stress.

Stress Corrosion: The preferential attack of areas under tensile stress in a corrosive environment, where such an environment alone would not have caused corrosion. Tensile stresses may be residual stresses from welding or cold-working or applied working stresses.


Strip and Blow Dry: All liquid removed from cargo tanks, tanks and lines blown dry. Strip and Squeegee: Barge is stripped then squeegeed; tanks are not dry; sales to specify in comments if “squeegee only” is required. Only applicable to lubes. Strip Overhead: Shipyard or qualified boat to strip as well as possible and then use stripping wand and/or mops to get remaining visible liquid. There may be product left where it can’t be seen or reached. Barge is not dry. May incur vapor control charges if at a shipyard. Stripping: Removal of bottoms from a barge after completion of discharge of product to a dock. Stripping System: A piping system on a barge that will remove bottoms after discharging, and store the bottoms in a slop tank.

Stripe Coating: Used to produce a coating with sufficient film thickness on edges, corners, weld seams and other areas that are difficult to coat using airless spray.

Structural Testing or Tank Testing: A hydrostatic test carried out to demonstrate the structural adequacy of design and tightness of tank boundaries.

Substantial Corrosion: An extent of corrosion such that assessment of corrosion pattern indicates wastage in excess of 75% of allowable corrosion, but within allowable corrosion limits.

Survey: A critical examination or inspection of a vessel, cargo, or marine structure for the purpose of ascertaining desired facts and conclusions when necessary.

Survey, Condition: A survey that determines in some detail the specific condition of a vessel or of cargo; usually performed at the commencement or termination of charters or voyages for the agreed mutual benefit of various parties.

Survey, Damage: A survey that determines the exact extent of damages incurred and specifies repair requirements.

Survey Report: The written evidence of the survey.

Survey, Suitability: A survey that determines whether a vessel and its equipment are capable of adequately and safely performing an intended task.

Survey, Trip and Tow: A survey in which the surveyor has full responsibility for inspecting and approving the suitability of the towing vessel, its gear and its tow, the loading and lashing of the cargo, and the navigational procedures, all in relation to the trip intended.

Survey, Valuation: A survey that determines the current market value and may also express replacement value.


Surveyor (Marine Surveyor): A qualified marine inspector who performs surveys / inspects a ship hull or its cargo for damage or quality.

Suspect Areas: Locations showing substantial corrosion and/or are considered to be prone to rapid wastage.


SWAD: Salt Water Arrival Draft

SWDD: Salt Water Departure Draft


Taut: With no slack; strict as to discipline


Tagout: The placement of a tag device on an energy isolating device, in accordance with the established procedure, to indicate that the energy isolating device and the equipment being controlled may not be operated or used until the tag device is removed. Tank: An enclosed space used for holding liquids. Tank Barge: A vessel specifically designed to carry bulk liquids. Tankering: The act of loading or transferring product into a barge or discharging or transferring product from a barge. Tankerman: A person licensed by the U.S. Coast Guard to transfer product to or from a barge.

TBN (To Be Nominated): When the name of a vessel is still unknown.


TCPA: Time to Closest Point of Approach.


Term (Time) Chartered Equipment: When the owner of the Vessel charters or leases the Vessel and its crew to the Charterer for a stipulated period; provided, however, under any such charter or lease, the Charterer pays for the bunkers and port charges in addition to the charter hire.


Terminal Party: The Party nominating the designated Shore Facilities at which the Vessel will load and/or discharge under the terms of the Agreement. Depending upon the nature of the sale, the Terminal Party may be either the Buyer or Seller.


Texas Deck: On an offshore jackup drilling rig, the deck below the rotary table and rig floor where workers can access the BOP stack. This platform surrounds the base of the BOP stack and is suspended from the cantilever (where the rig floor is located) by adjustable cables. It is accessed from the main deck of the jackup barge by a semipermanent stairwell. The Texas deck is used primarily for installing the wellhead and nippling the BOP stack up and down.


Texas Gulf: A grain export region including export elevators located in Beaumont, Brownsville, Channelview, Galena Park, Galveston, and Corpus Christi, TX.

THC (Terminal Handling Charges Time Charter): A contract for the services of a vessel for a specified period of time during which the primary control and management of the vessel remain with the owner.


Torsional Strength: The strength of the hull in resisting twisting about a longitudinal axis.


Tow: To push or pull vessels on a waterway; also refers to the unit composed of the towing vessel and the vessels being towed or only the vessels being towed. Any combination of tugs, push boats, or barges with the ability to function as a single unit.


Towing Lights: Two amber lights, one atop the other displayed at the stern of a towboat.

Towage: Charges for the services of tugs assisting a ship or other vessels in ports.

Towboat: A snub-nosed boat with push knees used for pushing barges. A small towboat (called a push boat) may push one or two barges around the harbor. A large towboat is used to push from 5 to 40 barges in a tow is called a line boat. From the Port of New Orleans, line boats deliver cargo to Mid-America via the 14,500-mile waterway system flowing through the Crescent City.


TPA: Third Party Auditor

Tramp (trade): A ship operating with no fixed route or published schedule.


Tramp Line: An ocean carrier company operating vessels on other than regular routes and schedules.

Tramp (tow): Tow Movement of barge(s) between two points by including it/them in a tow of a boat and other barges going in the same direction (contrast with “dedicated” tow). It is sometimes necessary to transfer barges being “tramped” from one boat to another to achieve the desired route and destination. Cost is generally less than the use of a “dedicated” boat, but control of the timing of barge movements is also less.


Transverse Planes: Vertical planes normal to the centerline plane of the ship. Transverse Stability: A measure of a ship’s stability in relation to rotation about a longitudinal axis.

Transverse Section: The intersections of transverse planes with the envelope of the ship’s hull. It includes, for thickness measurement purposes, all longitudinal members such as plating, longitudinals and girders at the deck, side, bottom, inner bottom and longitudinal bulkheads. For transversely framed ships, a transverse section includes adjacent frames and their end connections in way of transverse section. Also called Girthbelt.


Traveling Block: The set of sheaves that move up and down in the derrick. The wire rope threaded through them is threaded (or "reeved") back to the stationary crown blocks located on the top of the derrick. This pulley system gives great mechanical advantage to the action of the wire rope drilling line, enabling heavy loads (drill string, casing and liners) to be lifted out of or lowered into the well bore.


Trim: Term used to describe the draft of a vessel from bow to stern. If there is a difference it is said to be out of trim.

True North: The geographic north pole; the chart direction to the north pole, where on a globe, the lines of longitude converge.

True Wind: The actual speed and direction of the wind felt when standing still.


Tugboat (or Tug Boat): Strong V-hull shaped, relatively deep draft boat used for maneuvering ships into and out of port and to carry supplies. Tug boats are generally either model bow tugs or pushboats. As a ship is too powerful to pull up to the wharf on its own, it cuts power and lets the tug nudge it into the berth. Tugs are used primarily for pull towing and designed for navigation in open or unprotected waters. Generally barges are pushed by towboats / pushboats, not tugs.


Tugboats are generally categorized as:


  1. Ocean-going Model Bow Tugs: Designed for taking long trips crossing the ocean. They are normally deep draft and have a large single or double drum winch on the stern. The deep draft is more for stability, but also for accommodating the needed fuel and water required for the longer voyages. The winches they carry, can and will have a good bit of tow wire for connecting to the barges they are towing. They may have as much as several thousand feet of wire. An ocean-going model bow tug may tow anything from a single barge, to multiple barges, to ships, to offshore platforms.

  2. Inland Model Bow Tugs: Normally have shallow draft, no stern winches, and carry less fuel and ballast. They’re very versatile boats, and also normally smaller that ocean-going model bow tugs. Inland bow model tugs are used anywhere from working log rafts in the inland river and lakes to pushing barges like a push boat. Smaller inland bow model tugs are called day boats or lunch box boats because they are used during the day or maybe just one shift. It also mean that the crew will not live on the boat. Some of the bigger inland or bow model tugs are used as ship assist boat when the big ships come in to port.

  3. Integrated Tug (and Barge), abbreviated as ITB: This type of tug physically connects to the back of the barge, once the tug pulls into the spot inn order and be locked in place. The combined tug-and-barge travel together like a ship. This type of tug has fallen out of favor with the industry, as they tend to disconnected in rough seas. Articulated Tug (and Barge) units, abbreviated as ATB, offer a commercially viable alternative.


Turn Turtle: To capsize


Turnaround: In water transportation, the time it takes between the arrival of a vessel and its departure.


TVEL: Tank Vessel Examination.


Undermanned: Insufficient number of crew; shorthanded.

Undertow: A subsurface current in a surf.


Underway: Said of a vessel when not at anchor, nor made fast to the shore, or aground.

In motion from a standstill. Unit Tow: A three-barge, integrated tow consisting of bow, center and stern sections.

Unitization: The consolidation of a quantity of individual items into one large shipping unit for easier and faster handling through methods such as palletizing, stripping, slinging and containerization.


U.S.C.G.: The United States Coast Guard.


U. S. Army Corps of Engineers (USACE): This department of the U. S. Army is responsible for flood protection and providing safe navigation channels. The Corps builds and maintains the levees, flood walls and spillways that keep major rivers out of low lying communities. The Corps is vital to keeping navigation channels open by dredging sand, silt and gravel that accumulate on river and harbor bottoms. USACE Mission: Deliver vital public and military engineering services; partnering in peace and war to strengthen our Nation’s security, energize the economy and reduce risks from disasters. USACE Vision: Engineering solutions for our Nation’s toughest challenges.


U.S. Flag Commercial Vessel: A vessel registered and operated under the laws of the United States; used in commercial trade of the United States; owned and operated by U.S. citizens, including a vessel under voyage or time charter to the Government; and a Government-owned vessel under bareboat charter to, and operated by, U.S. citizens.

U.S. Gulf: An area that includes Mississippi Gulf, Texas Gulf, and East Gulf.


UU: Unless Used

UUIUATUTC: Unless Used If Used Actual Time Used To Count


Vapor Controlled Transfer: Vapors returning from a barge to a dock, shore tank, or vented through the vent stack. Vapor Tightness Certificate: Document indicating a barge has been pressure tested for vapor tightness in the last twelve (12) months.


Vernier Scale: A scale used to obtain a precise reading of an instrument, particularly for mariners, of the altitude readings on a sextant.


Vertical Center of Gravity (VCG): an important computation used in the determination of the stability of a vessel with its cargo.


Vessel: Any Tow, Inland Barge, Ocean-Going Barge, or Ocean Tanker, or other marine vessel carrying the Cargo under the Agreement. References herein to “Vessel(s) Account” and responsibilities, duties, rights and liabilities of the “Vessel” are intended to include not only the Vessel itself, but also the owner, operator, master, or agent of such Vessel, where applicable.


VEF: Vessel Experience Factor.


Vessel Manifest: The international carrier is obligated to make declarations of the ship’s crew and contents at both the port of departure and arrival. The vessel manifest lists various details about each shipment by B/L number. Obviously, the B/L serves as the core source from which the manifest is created.


Vessel Party: The Party nominating the Vessel that will carry the Cargo under the terms of the charterparty agreement. Depending upon the nature of the sale, the Vessel Party may be either the Buyer or Seller.


Vessel Response Plan (VRP): A U.S.C.G. approved set of guidelines for responding to a spill or potential spill of oil from tank vessels, including training and testing procedures, as mandated in the Oil Pollution Act of 1990.


Vessel Security Plan (VSP): A U.S.C.G. approved set of guidelines providing for the secure operation of regulated vessels under various levels of national security warning levels, including specific protections, defenses and procedures as mandated by the Maritime Transportation Security Act of 2002.


Vessel Traffic Control (VTC): a central control system used in some ports to safely direct navigation.


Viscosity: A property of fluids and slurries that indicates their resistance to flow, defined as the ratio of shear stress to shear rate. Viscosity can be expressed mathematically as follows: Poise is the unit for viscosity, equivalent to dyne-sec/cm2. Because one poise represents a high viscosity, 1/100 poise, or one centipoise (cp), is used for mud measurements. One centipoise equals one millipascal-second. Viscosity must have a stated or an understood shear rate in order to be meaningful. Measurement temperature also must be stated or understood.

VP: Voyage Plan

VPD: Vessel Protection Detachment

VPD: Vessel Pays Dues

VPQ: Vessel Particulars Questionnaire

VRM: Variable Range Marker

VTS: Vessel Tracking System


Yaw: To steer wildly or out of line of course.

Yield Stress: Stress limit within a material at which plastic (permanent) strain commences under load.

Z-drive: Propulsion train configuration where the engine output and propeller shafts are horizontal and parallel and linked via an intermediate vertical shaft. Zee-bar: A structural shape with a cross section resembling the letter Z.

Zenith: When the sun is in the zenith and observed with a sextant, the arc will be 90o from the horizon.

Zinc Primer: Common corrosion inhibiting primer used to coat bare steel prior to subsequent paint coatings being applied.


Water Line(s): The line painted on the side of the vessel at the water’s edge to indicate the proper trim. Lines drawn parallel with the surface of the water at varying heights on a ship’s outline. In the sheer plan they are straight and horizontal, in the half-breadth plan they show the form of the ship at each of the successive heights marked. Waterlogged (Water-logged): A ship full of water but still afloat. Filled with water but afloat. Water’s Edge: The surface of the water.


Watertight: Of such construction or fit as to prevent the passage of water, except when structural discontinuity, physical rupture, or purposeful opening may occur. It also means capable of preventing the passage of water through the structure under a head of water for which the surrounding structure is designed.


Way Bill: The document used to identify the shipper and consignee, present the routing, describe the goods, present the applicable rate, show the weight of the shipment, and make other useful information notations.


Wear: The deterioration of a surface due to relative motion between it and another.


Weather Eye: To keep a weather eye is to be on the alert (heads up).

Weather Helm: The natural tendency of a sailboat to turn toward the wind, which the helmsman feels as the tiller tries to turn to leeward.


Weather Side: The windward side (from where the wind is blowing).

Weathertight: Capable of preventing the ingress of water in any wind and wave conditions up to those specified as critical design conditions; in any sea condition water will not penetrate into the ship.


Weeping: The very slow issuance of water through the seams of a ship’s structure or from a containing vessel in insufficient quantity to produce a stream.

Weld Metal Corrosion: A preferential corrosion of the weld deposit due to an electrolytic action between the weld metal and base metal.


Wharfage (Whfge.): Charge assessed by a pier or dock owner against freight handled over the pier or dock or against a steamship company using the pier or dock.


Where Away: A call requesting direction in answer to the report of a lookout that an object has been sighted.


Windbound: When a tow stops due to high wind and the boat does not have enough power to keep the tow moving.

Whipping: A method of preventing the ends of a line from unlaying or fraying by turns of small stuff, stout twine or seizing wire with the ends tucked.


WHL (West of Harvey Lock): Used with mileage designations on the Gulf Intracoastal Waterway, Harvey Lock being mile zero.

White cap: The white froth on the crests of waves.

WIBON: Whether In Berth Or Not

Wide berth: At a considerable distance.

WIFPON: Whether In Free Pratique or not


Wind Rose: A diagram usually shown on pilot charts that indicates the frequency and intensity of wind from different directions for a particular place.

Windward: Toward the wind.


Wiper: A general handyman in the engine room.

Working End: The fastened or manipulated end of a line.


Worldscale: The tanker nominal freight scale applying to the carriage of oil in bulk as promulgated by Worldscale Association (London) Limited or Worldscale Association (NYC) Inc. (as applicable) or any successor thereto, in effect as of the date of the Agreement.


WQIS (Water Quality Insurance Syndicate): An underwriting agency formed by various insurance companies for the purpose of insuring against losses resulting from water pollution.

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