Glossary — B

44 terms starting with B.

• Backing
  An anti-clockwise shift in wind direction in the Northern Hemisphere, often indicating the approach of a low pressure system or cold front.
• Bahamian Moor
  Mooring with both bow anchors set roughly 180 deg apart, restricting the swing circle in tight anchorages.
• Ballast water
  Sea water taken into ballast tanks to stabilise a vessel — subject to strict management under the BWM Convention to prevent invasive species transfer.
• Ballast Water Management (BWM)
  The IMO framework requiring treatment or exchange of ballast water to prevent transfer of invasive marine species — implemented via the BWM Convention.
• Ballast Water Management Convention (BWM Convention)
  The 2004 IMO convention requiring ships to manage ballast water to prevent transfer of invasive aquatic species between regions.
• Ballast Water Record Book (BWRB)
  A mandatory log recording all ballast water uptake, treatment, exchange, and discharge operations under the BWM Convention.
• Ballast Water Standard D-1
  Ballast water exchange standard requiring at least 95% volume exchange in deep ocean water.
• Ballast Water Standard D-2
  Performance standard limiting viable organisms in discharged ballast; met by an approved ballast water management system.
• BAPLIE
  An EDI message format conveying the stowage positions of all containers aboard a vessel between terminals and ship operators.
• Bareboat Charter
  Demise charter where charterer takes full operational control, including crewing and maintenance, for a fixed period.
• barge
  Non-self-propelled flat-bottomed vessel pushed or towed by a tug, used on inland waterways and coastal routes to carry bulk, liquid, or project cargo.
• Basic Offshore Safety Induction & Emergency Training (BOSIET)
  OPITO-accredited 3-day course required for new offshore travellers; includes HUET, fire, escape, first aid.
• Basic Safety Training (BST)
  Mandatory STCW training covering personal survival, fire prevention, first aid, and personal safety for all seafarers.
• Bay Plan
  A grid diagram showing every container slot in a vessel's cross-section by bay, row, and tier with container data.
• Bearing
  The horizontal direction of one point from another, expressed in degrees from 000° to 359°.
• Beaufort Scale
  An empirical scale from 0 to 12 that relates wind speed to observed sea surface conditions and wave heights.
• Bergy Bit
  Medium fragment of glacier ice, 1–5 m above water and 5–15 m across.
• Berth
  A designated position at a wharf or quay where a vessel moors to load or discharge cargo or embark passengers.
• Best Management Practices 5 (BMP5)
  Joint industry guidance for protection against ship attacks in the Western Indian Ocean and Gulf of Aden / Arabian Sea.
• Bilge
  The lowest interior space of a vessel where leakage, condensation, and drainage water collects; must be pumped out regularly.
• Bill of Lading (B/L)
  A legal document issued by a carrier acknowledging receipt of cargo for shipment, serving as a receipt, title document, and contract of carriage.
• Bill of Lading — Types
  Order, bearer, straight, sea waybill — distinguishes how title/possession transfers and whether the document is negotiable.
• Biofouling Guidelines
  IMO guidelines for the control and management of ships' biofouling to minimise transfer of invasive aquatic species.
• Bitter End
  Inboard end of the anchor chain secured in the chain locker; from which 'to the bitter end' is derived.
• Block Coefficient (Cb)
  Ratio of underwater volume to a rectangular block of length × beam × draft.
• BMP West Africa
  Counter-piracy guidance for vessels transiting the Gulf of Guinea (current 'Global Counter Piracy Guidance for Companies, Masters and Seafarers').
• Boatswain's Mate
  Senior deck rating, deputy to the Bosun on larger ships; supervises deck crew, assists in cargo and safety operations.
• Boil-Off Gas (BOG)
  Vapour generated naturally as cryogenic cargo (LNG, LPG, ethylene, ammonia) absorbs heat through tank insulation and boils.
• Boil-Off Rate (BOR)
  Daily fraction of cryogenic cargo lost to boil-off, expressed as % of cargo mass per day.
• Bollard Pull (BP)
  Static towing force a tug can exert measured against a fixed bollard; primary spec for tugs (typically 30–100 t for harbour, 150–300 t for AHTS).
• Bosun
  Senior unlicensed deck rating responsible for the upkeep of deck equipment, mooring gear, and supervision of the deck crew.
• Bow Thruster
  A transverse propulsion unit fitted in a tunnel through the bow section to improve low-speed manoeuvrability in port.
• Break Bulk
  Non-containerised cargo loaded individually as bags, bales, crates, or drums rather than in standard containers.
• breakbulk vessel
  General cargo ship carrying non-containerised goods — bagged, crated, palletised, or bundled — loaded and discharged piece by piece.
• Breaking Load (BL) (BL)
  The tested load at which a securing device (rope, chain, wire) will fail — the certification-basis for MSL calculation.
• Bridge Alarm
  An alarm system on UMS vessels that channels all critical engine room and safety alarms to the navigating bridge when the engine room is unmanned.
• Bridge Log
  A watchkeeping record maintained on the bridge detailing courses steered, speed, weather conditions, and watch handovers.
• Bridge Resource Management (BRM)
  Non-technical-skills training in bridge teamwork, communication, decision-making, and human-factors error prevention.
• Broken Stowage
  The wasted space in a cargo hold that cannot be utilised due to the shape or packaging of the cargo being carried.
• Bulk Carrier
  A single-deck cargo vessel designed to carry unpackaged dry bulk cargoes such as grain, coal, iron ore, or fertiliser.
• Bulkhead
  Vertical partition dividing a ship into watertight compartments.
• Bunker
  Fuel oil carried aboard and consumed by a ship's main and auxiliary engines; also refers to the act of taking on fuel.
• Bunker Delivery Note (BDN)
  Document recording details of fuel oil delivered, including density, viscosity, sulphur content, and supplier ID.
• Bunkering
  The operation of taking fuel oil aboard a vessel, requiring careful monitoring of quantities, trim, and pollution prevention measures.