Module 18 - Signals & Communications
Radio Discipline
What you will learn
Prepare and transmit a concise marine VHF call while maintaining listening watch, lookout, vessel control and correct channel use.
Good radio work reduces interference and cockpit workload. Listen first, prepare the message, use appropriate power, identify the station and move routine conversation away from Channel 16.
Good VHF discipline is part of seamanship. Listen before transmitting, use low power when range allows, keep calls short, and move routine traffic to a working channel. Channel 16 must be kept clear for distress, urgency, safety, and calling.
Routine radio checks should not block distress channels. Use an appropriate local service, marina, harbour authority, or automated radio-check facility where available. Before a passage, brief the crew on how to make a distress call and where the vessel position is displayed.
Make a call without losing the approach
The yacht is closing a busy reporting point. The navigator must call harbour control while the helmsman needs a course update and the lookout has reported a crossing ferry.
1. Stabilise the task
Give vessel control and lookout explicit owners before starting menu or microphone work.
2. Prepare
Write the station, own identity, position or report, request and expected working channel.
3. Transmit and hand back
Listen, call concisely, move channel as instructed, read back critical details and return attention to the traffic picture.
Sense check: The radio exchange leaves the bridge team with a clearer traffic and action picture rather than a head-down operator and an unbriefed helm.
Common mistake or limitation
- High power is not the default for every local call; use low power first except for distress where appropriate.
- Do not hold push-to-talk while deciding what to say or fill Channel 16 with repeated routine calls.
- A radio check must use an appropriate service and must not obstruct distress and safety traffic.
- The radio operator must not become the only person who knows the received channel, instruction or reporting time.
Recap
- Listen before transmitting and identify the station and own vessel.
- Keep the call brief and use the appropriate power.
- Move routine conversation promptly to the working channel.
- Protect lookout and vessel control throughout the exchange.
Optional quick check
Section 10 of 18
Near a busy harbour, what should happen before the navigator begins a routine VHF call?
Sources and factual review
Reviewed 20 August 2026 - Compass Revision editorial review.
Continue studying Signals & Communications
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