Keep the ship station licence, applicable operator certificates, equipment instructions and required current service publications available. Exact carriage, display and retention requirements depend on the applicable rules and flag administration; the entire IMO reading list for an RCC is not automatically mandatory aboard every ship. Consult current GMDSS Master Plan and radio-service information before the voyage.
Record safety-significant communications, tests, false alerts and cancellations, equipment defects and corrective action with UTC date/time, relevant identities, channel or equipment, outcome and responsible operator. Keep corrections traceable. A normal ship MMSI is MIDxxxxxx; group ship identities start with 0 and coast station identities with 00. Do not invent station identities for real test calls or present example records as actual events.
A station is a controlled record
Radio-station management joins identity, authorisation, equipment instructions, current service information, and traceable records. The exact carriage and retention rules come from SOLAS and the flag administration. A learner can build a reliable record without pretending that one national checklist applies everywhere.
What a useful log entry contains
For study purposes, a safety-significant entry should let another operator reconstruct what happened. Include UTC date and time, the relevant identity, channel or equipment, event or test, result, defect or corrective action, and responsible operator where the applicable log requires it. Corrections should remain traceable. A neat example is not evidence that a real call occurred.
- 1Identify the station, equipment, or service involved.
- 2Record the event time in UTC and describe the event.
- 3Record the observed result, including any failure.
- 4Record who was responsible and what follow-up was assigned.
- 5Preserve the original entry and make corrections auditable.
| Record field | Why it helps | Typical uncertainty |
|---|---|---|
| UTC date/time | Orders events consistently | Clock accuracy and local log rules |
| Identity | Links event to station or service | Allocation and registration are external |
| Test/result | Shows what was observed | A local test may not prove end-to-end service |
| Defect/action | Supports follow-up | Repair acceptance belongs to responsible authority |
Identity without invention
ITU Radio Regulations Article 32.5A requires administrations to arrange assignment and registration of GMDSS ship identities and to make registration information available to rescue coordination centres continuously. That does not allow a learner to infer a real identity from a pattern alone. Use fictional values in a worksheet and label them as examples. Never make a real test call with invented data.
The station licence, operator certificates, equipment manuals, current GMDSS Master Plan material, and radio-service information each answer different questions. Availability of a document does not prove that it is the current document for this ship or voyage. A source shelf is a control, not a compliance certificate.
UTC versus inference
UTC is the timestamp convention used by the radio record in this lesson. It is a fact to record, while “the test proves the coast station received us” is an inference that needs separate evidence. Similarly, an equipment self-test can show the facility responded; it does not establish current coverage, legal carriage, or an RCC's operational status.
This distinction makes a study log useful without turning it into a false official record.
Sources: ITU RR 2024, Article 32.5A; MCA Master's Guide, GMDSS Log Book §§5.1–5.3; IMO GMDSS circular index.
Official references · 2026-09-09
Apply what you learned
A fictional weekly DSC test responds locally, but the exercise has no coast-station receipt. The learner must complete a sample record.
What may the record claim?
Suggested answer: It may claim that the local test response was observed at the stated UTC time; it must not claim coast-station receipt.
Why this works: The observation and the inference require different evidence. A traceable log helps the next operator investigate without overstating what the equipment test established.
Continue with guided radio exercises.
Practise in the radio simulatorKey Takeaways
Log entries should preserve UTC time, identity, equipment or channel, result, defects, action, and traceable corrections as applicable.
ITU identity registration is an administration function; numeric patterns do not authorise invented real identities.
MCA log and test examples are UK evidence and cannot be generalized to every flag.
A self-test proves only what that test observes; it does not prove legal compliance, coverage, or successful end-to-end service.
Common Mistakes
Presenting a fictional sample log as evidence of a real communication or test.
Treating the MCA cadence or a particular certificate as universal.
Confusing a recorded observation with an unsupported conclusion about coverage or compliance.
Test Your Knowledge
Practise this topic and review the explanation for each answer.
More GMDSS lessons
Last reviewed: