Module 18 - Signals & Communications
Advanced Scenario Check: Signals
What you will learn
Make a reversible communication and vessel-control plan for a lee-shore incident with uncertain VHF coverage, injury and a shrinking sea-room margin.
The advanced task is not to name one radio call in isolation. It is to protect sea room, divide the workload, communicate the current truth and escalate before the situation becomes forced.
A night yacht loses propulsion 1.4 nautical miles upwind of a lee shore. The fixed VHF powers up but the masthead antenna may have failed, one crew member has a painful arm injury, and the yacht is drifting towards a pre-briefed 0.8-nautical-mile limit. The handheld works at deck level but has not yet reached the Coastguard.
The command task is concurrent: create sea room or arrest the drift, care for the casualty, prepare an accurate position and choose a proportionate call while testing independent communication paths. PAN-PAN may fit while control and time remain; MAYDAY is required if grave and imminent danger develops and immediate assistance is needed.
A strong answer sets an early update and a measurable escalation gate. It does not wait for the shoreline to become visually frightening, promise handheld range, or spend the remaining margin fault-finding while no one owns the helm and anchor preparation.
Worked example
The skipper has four minutes before the projected drift reaches the pre-briefed gate.
- 1Minute 0: assign helm/lookout, anchor or other vessel-control preparation, casualty check, and position/communications roles.
- 2Minute 1: transmit the appropriate urgency message with position, drift, reduced radio capability, assistance needed and next update time.
- 3Minute 2: try the independent path, verify whether the control action is effective and report the measured result.
- 4Before the gate: escalate and act on the no-go plan if control is not proven; do not wait for the four-minute estimate to expire.
Sense check: The timeline protects a margin for action. It is a scenario scaffold, not a universal four-minute procedure for real vessels.
Use the 0.8-mile gate before it is crossed
The yacht is 1.4 nautical miles upwind of a lee shore, drifting towards a 0.8-mile no-go gate. Propulsion is lost, one arm injury is stable, the fixed antenna is doubtful and the handheld has not reached the Coastguard.
1. Act on the vessel
Prepare or deploy the suitable control measure, maintain lookout and verify the drift rather than spending the entire margin on radio diagnosis.
2. Communicate the truth
Use the proportionate priority, checked position, drift, injury and antenna limitation through each appropriate independent path.
3. Escalate by gate
Use MAYDAY if grave and imminent danger develops—such as failed control, crossed sea-room limit or casualty deterioration—and immediate assistance is needed.
Sense check: The plan remains safe if the handheld still fails to make contact and does not depend on an untested anchor or one injured operator.
Common mistake or limitation
- Do not diagnose the radio while no one owns the drift, traffic and shore hazard.
- PAN-PAN is not defended after the situation has crossed into grave and imminent danger requiring immediate assistance.
- A charted distance gate must be monitored and adjusted for position uncertainty, drift, sea state and the vessel's actual control response.
- This text scenario cannot demonstrate that a learner can operate an unfamiliar radio, deploy an anchor, brief a crew or perform under real pressure.
Recap
- Control the vessel and communicate concurrently.
- Report uncertainty and reduced capability, not just the incident label.
- Use independent paths and a timed next update.
- Escalate before the protected sea-room or casualty gate is consumed.
Optional quick check
Section 18 of 18
The anchor fails to arrest the drift and the yacht crosses the 0.8-mile gate. Which response best follows the brief?
Sources and factual review
Reviewed 20 August 2026 - Compass Revision editorial review.
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