Glossary — C

57 terms starting with C.

• Cadet
  A trainee officer serving aboard ship as part of an approved maritime academy programme to gain sea service for certification.
• Call Sign
  An ITU-assigned alphanumeric identifier used to identify a vessel during radio communications.
• Capesize
  Bulk carrier > 100,000 DWT — too large for Panama Canal, must round Cape of Good Hope or Cape Horn; iron ore, coal, bauxite trades.
• Capstan
  A vertical-axis powered drum on deck used to heave in mooring lines or warping lines.
• Carbon Intensity Indicator Rating (CII)
  Operational efficiency rating A–E assigned annually to ships >5,000 GT under MARPOL Annex VI.
• Cargo Control Room Operator (CCR Operator)
  An officer or rating on a tanker or bulk carrier who monitors and controls cargo loading, discharging, and ballasting operations from a centralised control room.
• Cargo Pump
  A large-capacity pump on a tanker used to discharge liquid cargo from cargo tanks to shore or to another vessel.
• Cargo Securing Manual (CSM) (CSM)
  The ship-specific manual required under SOLAS VI/5 + VII/6 documenting the cargo-securing arrangements + calculation methodology.
• Celestial Navigation
  The art and science of determining a vessel's position by measuring the altitudes of celestial bodies with a sextant.
• Certificate of Competency (CoC)
  Statutory licence issued by a flag state under STCW certifying a seafarer's qualification for a deck or engine rank.
• Certificate of Proficiency (CoP)
  STCW certificate for ratings and supporting-level functions (e.g., AB, RFPNW, fast-rescue boat).
• Certificate of Registry
  An official document issued by the flag state confirming the vessel's registration, nationality, and ownership details.
• Chart Datum
  The reference tidal level from which chart depths + drying heights are measured — typically Lowest Astronomical Tide (LAT) in modern charts.
• Charter Party (C/P)
  A contract between a shipowner and a charterer for the hire of a vessel or cargo space, setting out terms and conditions of the voyage.
• Chemical Distribution Institute (CDI)
  Chemical-tanker equivalent of SIRE: independent ship inspection scheme used by chemical major vetting departments.
• Chemical Tanker
  A tanker built to carry noxious liquid substances in bulk, constructed to IBC Code standards for cargo containment.
• Chief Engineer (C/E)
  The senior engineer officer responsible for the operation, maintenance, and safety of all machinery and technical systems aboard.
• Chief Mate (C/O)
  The officer second in command to the master, responsible for cargo operations, stability, deck maintenance, and crew safety.
• Chronometer
  A precision timekeeping instrument used in celestial navigation to provide accurate GMT for the calculation of longitude.
• CIRM (Centro Internazionale Radio Medico) (CIRM)
  The Rome-based international radio-medical assistance centre — the historical + most-used TMAS provider for merchant ships worldwide.
• Citadel
  Hardened safe room with food, water, and communications where crew can shelter during a piracy boarding while awaiting military intervention.
• Classification Society
  A non-governmental organisation that establishes and verifies structural and mechanical standards for ship construction and maintenance.
• Clearing Line
  A bearing or line on the chart that, when maintained, keeps a vessel clear of a specific hazard such as a shoal or reef.
• Closed-Loop Scrubber (EGCS)
  Exhaust gas cleaning system that uses caustic soda (NaOH) in a closed water loop to remove SOx; sludge stored aboard for shore disposal.
• CoC (Certificate of Competency) (CoC)
  The STCW certificate proving a seafarer meets the training + experience standard for a specific rank + capacity.
• Cold Lay-up
  A long-term idling of a vessel with systems shut down and crew reduced to a minimum, used when reactivation is uncertain.
• Collision Bulkhead
  Forward-most watertight bulkhead designed to limit flooding from bow damage.
• COLREG Rule 13 — Overtaking
  Any vessel overtaking another shall keep out of the way of the vessel being overtaken — applies regardless of relative status under other rules.
• COLREG Rule 14 — Head-On
  When two power-driven vessels meet on reciprocal courses, each shall alter course to starboard.
• COLREG Rule 15 — Crossing
  When two power-driven vessels are crossing so as to involve risk of collision, the vessel which has the other on her own starboard side shall keep out of the way.
• COLREG Rule 18 — Responsibilities
  Hierarchy of stand-on / give-way: power-driven vessels give way to sailing, sailing to fishing, fishing to NUC and RAM.
• COLREG Rule 19 — Restricted Visibility
  Conduct of vessels in or near restricted visibility — early action, safe speed, and avoidance of port-side alterations to a vessel forward of the beam.
• COLREG Rule 5 — Lookout
  Every vessel shall at all times maintain a proper lookout by sight and hearing as well as by all available means appropriate.
• COLREG Rule 6 — Safe Speed
  Every vessel shall proceed at a safe speed so she can take proper and effective action to avoid collision.
• COLREG Rule 7 — Risk of Collision
  Every vessel shall use all available means to determine if risk of collision exists; if in doubt, such risk shall be deemed to exist.
• COLREGs (International Regulations for Preventing Collisions at Sea) (COLREGs)
  The 1972 IMO convention setting the rules of the road for preventing collisions at sea — steering, sailing, lights, shapes, sound signals.
• Combination Ladder
  A pilot boarding arrangement combining a pilot ladder below with an accommodation ladder above to accommodate height differences.
• Common-Rail Injection
  Fuel-injection system where pressurised fuel is held in a high-pressure rail and injected per-cylinder via electronically controlled injectors.
• Company Security Officer (CSO)
  The shore-based person designated by a company to be responsible for developing and implementing its Ship Security Plans under the ISPS Code.
• Compass
  Instrument indicating direction relative to magnetic north or true north, fundamental to ship navigation.
• Compass Bearing
  A bearing measured by a ship's compass, requiring correction for both variation and deviation to obtain a true bearing.
• Compass deviation
  The error of the magnetic compass caused by the ship's own magnetic field — corrected via periodic swinging + adjustment.
• Concentrated Inspection Campaign (CIC)
  Time-limited PSC focus area (e.g., crew familiarisation, ballast water management) coordinated across MoUs.
• Container Ship
  A cargo vessel designed to carry ISO standard intermodal containers stacked in cells below deck and in tiers on deck.
• Continuous Survey Machinery (CMS)
  Class arrangement allowing machinery items to be surveyed in rotation by the chief engineer rather than in one yard period.
• Continuous Synopsis Record (CSR)
  Statutory document recording the history of a ship's flag, name, owner, ISM company and class society.
• Contract of Affreightment (COA)
  Long-term contract obliging the carrier to lift a stated quantity of cargo over a defined period using nominated tonnage.
• Controllable Pitch Propeller (CPP)
  A propeller whose blade pitch can be varied in service, allowing speed and thrust control without changing engine rotation direction.
• Cool-Down
  Gradual cooling of LNG/LPG cargo tanks with cargo vapour before loading to prevent thermal shock to membrane / pressure vessel walls.
• CoP (Certificate of Proficiency) (CoP)
  A STCW certificate covering a specific function (BST, AFF, MFA) rather than a rank — held by both officers + ratings.
• CPA (Closest Point of Approach) (CPA)
  The minimum distance between own ship + a target — a primary radar/ARPA collision-risk indicator.
• Crankcase
  The lower enclosed section of an engine housing the crankshaft, connecting rods, and bearing lubrication system.
• Crude Oil Washing (COW)
  A tank cleaning method using crude oil cargo as the washing medium to dissolve and remove waxy residue from tank surfaces.
• Crude Oil Washing (COW)
  Cleaning crude oil tanks with their own cargo as the wash medium, replacing earlier seawater-flush methods.
• Cruise Ship
  A large passenger vessel offering multi-day voyages with onboard leisure facilities as the primary commercial product.
• Cumulonimbus (CB)
  A deep, vertically developed convective storm cloud extending to the tropopause, producing squalls, lightning, heavy rain, and microbursts.
• Custody Transfer (CT)
  Measurement and transfer of cargo from seller to buyer in a contractually-binding way, conducted by a third-party surveyor.