Module 18 - Signals & Communications
Relay and Acknowledgement
What you will learn
Receive distress traffic without interference, apply the five-minute voice-acknowledgement condition and relay facts without creating a second casualty.
Reception is an active task: stop interfering transmissions, listen, write the facts and let the coordinating station control the exchange. Assistance is offered only within the vessel's real capability.
If distress information has not reached a station able to coordinate help, or the casualty cannot transmit effectively, you may need to relay it. A MAYDAY RELAY passes on the facts so an appropriate coast station can receive them. Do not block an active rescue exchange unless you have essential information.
When acknowledging a distress alert or call, be concise. Give your vessel name, position, ability to assist, and estimated time to the casualty if relevant. If you cannot assist safely, say so. A skipper must avoid turning one emergency into two.
Handle an unacknowledged DSC alert
A DSC alarm sounds. No coast-station acknowledgement follows, the voice MAYDAY is weak, and your yacht may be able to reach the casualty in forty minutes.
1. Listen and record
Cease interfering transmissions, monitor Channel 16 and write identity, position, time, distress and any coordinator.
2. Apply the condition
If no DSC acknowledgement follows after five minutes and you can offer assistance, acknowledge by voice as the MCA procedure permits.
3. Relay and qualify
Use any available means to relay the facts to an appropriate coast station and state a safe, evidence-based assistance capability.
Sense check: The log separates words heard from the casualty, instructions from the coordinator and the receiving yacht's own estimates.
Common mistake or limitation
- An immediate small-craft acknowledgement can interfere with coast-station coordination; listen and follow the published timing condition.
- Do not improve, round or infer the casualty's coordinates, identity or persons-on-board figure.
- Being the nearest vessel does not automatically make an approach or tow safe.
- MAYDAY RELAY is for passing distress information, not for routine engine trouble or a general weather request.
Recap
- Stop interference and listen on Channel 16.
- After five minutes without DSC acknowledgement, voice-acknowledge only if able to offer assistance.
- Relay the factual message to an appropriate coast station by any available means.
- Report limits and a safe ETA; do not turn one casualty into two.
Optional quick check
Section 5 of 18
A distress alert has no acknowledgement after one minute. What is the best immediate action for a small yacht?
Sources and factual review
Reviewed 20 August 2026 - Compass Revision editorial review.
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