Maritime glossary: seafarer certificates and terms A to Z

1 In short

Short definitions of the words seafarers meet in vacancies, certificates and contracts, from STCW and CoC to SIRB and hours of rest. Each term has its own anchor, so a link can point straight to it, and each definition cites the rule it comes from. National names are given where a country uses its own, such as SIRB, CDC or MMC.^1,2

Most searched terms

• STCW
• CoC
• CoP
• BST
• PSCRB
• GMDSS
• ECDIS
• SIRB
• CDC
• MLC 2006
• OOW
• AB

2 Certificates and documents

CoC – certificate of competency

The certificate a master, officer or GMDSS radio operator holds to serve in a capacity at a stated level of responsibility; only the Administration issues it. CoC vs CoP³

CoP – certificate of proficiency

Any other STCW certificate issued to a seafarer, stating that training, competence or sea service requirements have been met, such as a watch rating certificate or basic safety training. CoC vs CoP⁴

Documentary evidence

Documentation other than a certificate of competency or proficiency, used to establish that a requirement of the STCW Convention has been met.⁵

Endorsement – endorsement attesting the issue or the recognition of a certificate; for recognition also “flag state endorsement”

A document attesting the issue of a certificate, or its recognition by another flag State; it expires with the certificate and in any case no more than five years after its issue. Recognition endorsement⁶

Revalidation

Keeping a certificate of competency valid: at intervals not exceeding five years the holder meets the medical fitness standards and shows continued professional competence. How to revalidate⁷

Medical certificate – medical fitness certificate

Proof of medical fitness for duties at sea, valid for no more than two years, or one year for seafarers under 18; national forms include the UK ENG1. Seafarer medical examination^8,9

Seaman’s book – discharge book, sea service record book

A record of a seafarer’s service on board ships, used to prove sea service for the next certificate. Seaman’s book¹⁰

SIRB – Seafarer’s Identification and Record Book

The name some flag States, for example Liberia, give to the seaman’s book. Seaman’s book¹¹

CDC – Continuous Discharge Certificate

In India, the record of a seafarer’s employment on board, issued under the Merchant Shipping (Continuous Discharge Certificate) Rules, 2026.¹²

MMC – Merchant Mariner Credential

The credential the United States issues to merchant mariners under title 46 of the Code of Federal Regulations, part 10.¹³

SID – seafarers’ identity document

An identity document for seafarers issued under ILO Convention No. 185, or under the earlier Convention No. 108. Seafarers’ identity document^14,15

TRB – training record book

The approved book in which a cadet’s onboard training is recorded; 12 months of sea service in a programme documented in it counts towards the officer of the watch certificate. Training record book^16,17

Seagoing service – sea time

Service on board a ship relevant to the issue or revalidation of a certificate or other qualification.¹⁸

3 Safety and special training

BST – basic safety training, STCW basic training

The training for seafarers with safety or pollution-prevention duties: personal survival techniques, fire prevention and fire fighting, elementary first aid, and personal safety and social responsibilities. Basic Safety Training^19,20

PST – personal survival techniques

The part of basic safety training on survival at sea if the ship is abandoned; competence is shown every five years.²¹

FPFF – fire prevention and fire fighting

The part of basic safety training on preventing and fighting fires on board; competence is shown every five years.²²

EFA – elementary first aid

The part of basic safety training on taking immediate action in an accident or other medical emergency.²³

PSSR – personal safety and social responsibilities

The part of basic safety training on emergency procedures, safe working practices, communication and relationships on board; since 01/01/2026 it also covers violence and harassment. STCW in 2026²⁴

PSCRB – proficiency in survival craft and rescue boats

A certificate of proficiency for survival craft and rescue boats other than fast rescue boats, issued from 18 after 12 months of sea service, or 6 months with an approved course. Survival craft and rescue boats²⁵

FRB – proficiency in fast rescue boats

A certificate of proficiency in fast rescue boats; the candidate must already hold the survival craft and rescue boats certificate. Fast rescue boats²⁶

AFF – advanced fire fighting

Training for seafarers designated to control fire-fighting operations, with emphasis on organization, tactics and command. Advanced Fire Fighting²⁷

MFA – medical first aid

Training for seafarers designated to provide medical first aid on board. Medical First Aid²⁸

Medical care

Training for seafarers designated to take charge of medical care on board. Medical Care on Board Ship²⁹

SSA – security awareness training

Security-related familiarization and security-awareness training for every seafarer; where it is not part of another qualification, a certificate of proficiency is issued. Security Awareness Training³⁰

DSD – designated security duties

Security training for seafarers who have designated security duties on board. Designated security duties³¹

SSO – ship security officer

The person on board, accountable to the master, designated by the company as responsible for the security of the ship, including the ship security plan; a certificate of proficiency is issued after 12 months of sea service or appropriate sea service and knowledge of ship operations. Ship Security Officer³²

ECDIS – electronic chart display and information system

Officers who keep a navigational watch on ships fitted with ECDIS need generic ECDIS training and familiarization with the equipment installed on the ship. Generic ECDIS trainingType-specific familiarization^33,34

GMDSS – Global Maritime Distress and Safety System

The system for distress and safety radio communications; a GMDSS radio operator is qualified under chapter IV of the STCW annex and holds a certificate under the ITU Radio Regulations. GOCROC^35,36

GOC – general operator’s certificate

The full GMDSS radio operator certificate under the ITU Radio Regulations and STCW regulation IV/2. General Operator’s Certificate³⁶

ROC – restricted operator’s certificate

The restricted GMDSS radio operator certificate under the ITU Radio Regulations and STCW regulation IV/2. Restricted Operator’s Certificate³⁷

BRM – bridge resource management

Knowledge of bridge resource management principles required of deck officers at the operational and management levels. Bridge Resource Management³⁸

ERM – engine-room resource management

Knowledge of engine-room resource management principles required of engineer officers at the operational and management levels. Engine-Room Resource Management³⁹

Basic tanker training – tanker familiarization

Basic training for oil and chemical tanker cargo operations (STCW V/1-1) or liquefied gas tanker cargo operations (STCW V/1-2) for seafarers with duties related to cargo or cargo equipment. Oil and chemical tankersGas tankers^40,41

DCE – dangerous cargo endorsement, advanced tanker training

The name often used for advanced training for tanker cargo operations under STCW V/1-1 and V/1-2. It is required of the master, chief engineer officer, chief mate and second engineer officer of a tanker and of anyone with immediate responsibility for its cargo operations. Advanced oil tanker training^42–44

IGF Code training

Basic and advanced training for service on ships subject to the IGF Code, which use gases or other low-flashpoint fuels. IGF Code basic training^45,46

Polar Code training

Basic training for masters, chief mates and officers in charge of a navigational watch on ships operating in polar waters, and advanced training for masters and chief mates. Polar waters basic training^47–49

High voltage training

Training on high-voltage installations for engineer officers and electro-technical officers, at the operational and management levels. High voltage, management level^50,51

4 Ranks and levels

Master – captain

The person having command of a ship. Master⁵²

Chief mate – chief officer

The officer next in rank to the master, upon whom the command of the ship falls if the master is incapacitated. Chief Officer⁵³

OOW – officer in charge of a navigational watch

A deck officer certified under STCW regulation II/1; on ships of 500 GT or more the certificate is issued from 18. Officer of the Watch⁵⁴

Chief engineer

The senior engineer officer responsible for the mechanical propulsion and the operation and maintenance of the mechanical and electrical installations of the ship. Chief Engineer⁵⁵

Second engineer

The engineer officer next in rank to the chief engineer, upon whom that responsibility falls if the chief engineer is incapacitated. Second Engineer⁵⁶

EOOW – officer in charge of an engineering watch

An engineer officer certified under STCW regulation III/1 to keep an engineering watch on ships with main propulsion machinery of 750 kW or more. Engineer Officer of the Watch⁵⁷

ETO – electro-technical officer

An officer qualified under STCW regulation III/6, responsible for electrical, electronic and control engineering on board. Electro-Technical Officer^58,59

ETR – electro-technical rating

A rating qualified under STCW regulation III/7. Ship’s Electrician⁶⁰

Rating

A member of the ship’s crew other than the master or an officer.⁶¹

RFPNW – rating forming part of a navigational watch, watch rating

A deck rating certified under STCW regulation II/4 to stand a navigational watch on ships of 500 GT or more; the certificate is issued from 16, and ratings under training are exempt. Watchkeeping Seaman⁶²

RFPEW – rating forming part of an engineering watch

An engine rating certified under STCW regulation III/4 to stand an engine-room watch on ships of 750 kW or more; ratings under training are exempt. Watchkeeping Motorman⁶³

AB – able seafarer deck, able seaman

A deck rating qualified under STCW regulation II/5: a watch rating with further sea service in the deck department, from 18. Able Seafarer Deck⁶⁴

Able seafarer engine – oiler

An engine rating qualified under STCW regulation III/5. Oiler⁶⁵

OS – ordinary seaman

An entry-level deck rating. The STCW Convention does not define the rank; a rating under training on watch does not need a watch rating certificate. Ordinary Seaman⁶⁶

Wiper

An entry-level engine-room rating. A rating under training or with unskilled duties in the engine room does not need a watch rating certificate. Wiper⁶³

Cadet

A trainee officer on an approved onboard training programme recorded in a training record book. Deck CadetEngine Cadet^16,67

Bosun – boatswain

The senior deck rating. The STCW Convention has no separate bosun certificate: deck ratings hold the watch rating and able seafarer deck certificates. Bosun⁶⁸

Management level

The level of responsibility of a master, chief mate, chief engineer or second engineer.⁶⁹

Operational level

The level of responsibility of an officer in charge of a navigational or engineering watch, a designated duty engineer, an electro-technical officer or a radio operator, under the direction of the management level.^70,71

Support level

The level of responsibility of a seafarer performing assigned tasks under the direction of the operational or management level.⁷²

5 Conventions and codes

STCW – International Convention on Standards of Training, Certification and Watchkeeping for Seafarers, 1978

The IMO convention that sets minimum standards of training, certification and watchkeeping for seafarers; it was comprehensively revised by the 2010 Manila amendments, in force since 01/01/2012. STCW Convention explainedSTCW in 2026⁷³

STCW Code

The code that supplements the regulations of the STCW annex: part A is mandatory, part B is guidance to be taken into account.⁷⁴

STCW-F – Convention on Standards of Training, Certification and Watchkeeping for Fishing Vessel Personnel, 1995

The convention for fishing vessel personnel; its revised annex and the STCW-F Code have been in force since 01/01/2026. STCW-F Convention^75,76

MLC 2006 – Maritime Labour Convention

The ILO convention on seafarers’ working and living conditions, including minimum age, medical certificate, recruitment and placement, employment agreements and hours of work and rest. MLC 2006 explained⁷⁷

ISPS Code – International Ship and Port Facility Security Code

The security code adopted in 2002 under SOLAS; the ship security officer and the security training of seafarers are tied to it.⁷⁸

6 Employment

SEA – seafarers’ employment agreement

The agreement signed by the seafarer and the shipowner or the shipowner’s representative; the seafarer may examine it and seek advice before signing and keeps a signed original.⁷⁹

Crewing agency – manning agency, recruitment and placement service

A service that recruits seafarers and places them with shipowners. No fees or other charges for recruitment or placement may be borne by the seafarer; the only costs the seafarer may bear are those of obtaining his or her own national statutory medical certificate, national seafarer’s book and passport, while visa costs are borne by the shipowner.⁸⁰

Hours of rest

Under STCW, watchkeepers and seafarers with designated safety, pollution-prevention or security duties must have at least 10 hours of rest in any 24-hour period and 77 hours in any 7-day period, in no more than two periods, one of them at least 6 hours long. Under the MLC 2006 the limits cover every seafarer: the flag State sets either these minimum hours of rest or maximum hours of work of 14 hours in any 24-hour period and 72 hours in any 7-day period.^81,82

7 Frequently asked questions