Backhaul - A deviation to move cargo on the return leg of a voyage for the purpose of minimizing ballast mileage and thereby reducing transportation cost.

Ballast - Seawater taken into a vessel's tanks in order to submerge the vessel to proper trim. Ballast can be taken into cargo tanks, double bottoms, fore and aft peak tanks and/or segregated ballast tanks, (SBT).

Clean - Term applied to the seawater used for ballast when it is not contaminated by any oil and is carried in clean tanks.

Dirty - Term applied to the sea water used for ballast when it is contaminated with the remnants or residue left in cargo tanks that previously carried crude oil or heavy persistent refined oils.

Permanent - Ballast carried in ship's tanks that were designed to carry nothing else.

Segregated/Dedicated - Ballast kept in tanks segregated from cargo pipes and tanks.

Ballast Movement - A voyage or voyage leg made without any paying cargo in a vessel's tanks. To maintain proper stability, trim, or draft, seawater is usually carried during such movements.

Ballast Passage - The "ballast leg" of a voyage as differentiated from the "loaded leg."

Ballast Pump - A pump used for filling and emptying the ballast tank.

Ballast Tanks - The tanks used to carry the vessel's ballast. They may be permanent, dedicated, or cargo tanks.

Bare Boat Charter - A Charter in which the bare ship is chartered without crew; the charterer, for a stipulated sum taking over the vessel with a minimum of restrictions usually for 10 or more years. See Demise Charter.

Barge - Also lighter. A general name given to a flat-bottomed craft specially adapted for the transportation of bulk cargoes.

Barrel - The standard unit of liquid volume in the petroleum industry. It is equal to 42 U.S. gallons.

Beam - The width of a ship. Also called its breadth.

Berth - Dockage space for vessel. Sleeping quarters. Also slang for having a crew position on the vessel

Bilge - The lower internal part of the hull where the vertical sides meet the bottom. This term applies to both the inside and the outside of the hull. The internal space can be the lower part of a ship's hold or the engine room and serves as a drainage area where accumulated water can run into and be pumped from.

Bill of Lading - A B/L is the basic document between a shipper and a carrier and a shipper and consignee. It represents the contract of carriage and defines the terms and conditions of carriage. It is the final receipt from the carrier for the goods shown on it and for the condition of the goods. It describes the nature, quantity and weight of the cargo carried. It is also the document of title of the goods shown.

BIMCO - Baltic and International Maritime Council

Bitts - Cast steel heads serving as posts to which mooring lines and cables are secured on a ship.

Boilers - Steam generating units used aboard ship to provide steam for propulsion or for heating and other auxiliary purposes.

Boiler Room - Compartment in which the ship's boilers are located.

Bonded Bunkers - Ship's stores that can be delivered under special arrangement direct from a bonded warehouse to the vessel without payment of the custom duties.

Bonded Stores - Ship's stores that can be delivered under special arrangements direct from a bonded warehouse to the vessel without payment of the customs duties.

Boom - A general name given to a projecting spar or pole that provides an outreach for handling cargo.

Bow - The forward most part of a vessel. This area usually houses gear lockers and is the end where anchors and mooring equipment are located.

Breadth - See Beam

Bridge - A general term referring to that area of a vessel where the wheel house and chart room are located. It is the navigating section of a vessel.

Bridge AFT - Vessels with no midship house. All quarters with Bridge are contained in one superstructure at after end of vessel.

Bulbous Bow - A large protruding bow section designed to break water friction allowing the vessel to make better speeds.

Bulk Cargo - Usually a homogeneous cargo stowed in bulk, and not enclosed in any container.

Bulkhead - A partition in a ship that divides the interior space into various compartments in the walls of a vessel's tanks.

Bum Boat - A small open rowboat employed in carrying supplies for sale to vessels in a harbor.

Bunkers - Fuel for a vessel. The type will vary depending upon the propulsion mode of the vessel. Steamships will use a heavy fuel oil, diesels use a range of fuels from heavy to light, and gas turbines generally use kerosene.

Buoy - A floating object employed as an aid to mariners to mark the navigable limits of channels, their fairways, sunken dangers, isolated rocks, telegraph cables, and the like.

Butterworth Tank Cleaning System - A mechanical device used for the purpose of cleaning oil tanks by means of high pressure jets of hot water. The apparatus basically consists of double opposed nozzles which rotate slowly about their horizontal and vertical axis and project two streams of water through all possible angles against all inside surfaces of the space being cleaned. The tank washing machines can deliver sprays of water at various temperatures and pressures that are dictated by the type of cargoes carried and the reasons for cleaning.