Module 12 — Maritime English for GMDSS

Use IMO Standard Marine Communication Phrases to reduce ambiguity. Say identities and coordinates clearly, including degrees, minutes, decimal points and hemisphere. Use UTC and read MMSIs digit by digit. The radiotelephony spelling alphabet and figure code are in ITU Radio Regulations Appendix 14; miscellaneous abbreviations and Q-codes are in ITU-R M.1172.

SAY AGAIN requests repetition. REPEAT can emphasize important information and is explicitly used in SMCP; it is not forbidden at sea. OVER expects a reply; OUT ends the exchange. The eight message markers are INSTRUCTION, ADVICE, WARNING, INFORMATION, QUESTION, ANSWER, REQUEST and INTENTION. Plain, understandable emergency information remains essential when a speaker cannot use the standard phrases perfectly.

Clarity is a safety function

Maritime English in GMDSS is disciplined communication under noise, stress, accents, and incomplete information. IMO Standard Marine Communication Phrases (SMCP) provide a controlled vocabulary for common maritime situations. They reduce ambiguity, but they do not repair a wrong coordinate, an incorrect identity, or an unavailable service. Plain, understandable emergency language remains necessary when the speaker cannot recall a formal phrase.

Use the formal tools carefully

ITU Radio Regulations Article 32.6 calls for radiotelephony to be slow and distinct. Article 32.7 points to the phonetic alphabet and figure code in Appendix 14, and to ITU-R M.1172 where applicable. The same provision recommends SMCP where appropriate and warns that figure pronunciation in ITU and SMCP differs. Name the source behind a phrase rather than treating pronunciation as an informal preference.

Use this reasoning workflow:

1. 1Decide whether the communication is distress, urgency, safety, or routine.
2. 2Choose the formal phrase only if it expresses the intended action.
3. 3Spell an identity or word with the applicable phonetic alphabet.
4. 4Send coordinates and numbers at a pace that permits transcription.
5. 5Confirm the response expected by the phrase and correct misunderstandings.

Coordinates and identities

Read a fictional MMSI digit by digit, spell a vessel name with the applicable alphabet, and attach UTC to a position. For example: “THIS IS VESSEL ALFA BRAVO CHARLIE. MY POSITION IS FOUR ONE DEGREES TWO TWO DECIMAL FOUR MINUTES NORTH, ZERO ZERO EIGHT DEGREES FOUR THREE DECIMAL ONE MINUTES WEST, AT ONE TWO ONE ZERO UTC.” A receiving operator can then use SAY AGAIN to request repetition, or REPEAT to restate important information in context. OVER invites a reply; OUT ends the exchange. Do not combine them into a memorised “OVER and OUT” formula. The exercise is accurate copying, not accent imitation.

Message markers

SMCP message markers such as INSTRUCTION, ADVICE, WARNING, INFORMATION, QUESTION, ANSWER, REQUEST, and INTENTION tell the listener how to interpret what follows. They are useful when the action or expected response could otherwise be unclear. A marker is not a magic safety guarantee: the following content still has to be true, current, and understood.

Compare two almost-correct messages and choose the one that preserves source, age, and requested action. This tests communication reasoning rather than accent or memorisation alone.

Sources: IMO SMCP A.918(22); ITU RR 2024, Articles 32.6–32.7; ITU RR Appendix 14; ITU-R M.1172.

Official references · 2026-09-09

IMO SMCP A.918(22) · ITU RR Appendix 14