Module 20 - Special Situations Afloat
Engine Failure
What you will learn
Separate immediate vessel control from bounded engine diagnosis and escalate before sea room, visibility or crew capacity is consumed.
An engine stop near hazards is first a navigation casualty. Create a stable vessel state, state the drift and time available, then run only the checks that the vessel manual and conditions support.
The first question is not 'why did it stop?' but 'what happens to the yacht now?' Establish position, depth, drift, traffic, weather, remaining propulsion and the nearest loss-of-control boundary. Use sail, reduce sail, heave-to, anchor or another already understood control when appropriate to the yacht and available water.
Assign helm, lookout/navigation, communications and machinery roles. One person troubleshooting must not remove the only effective lookout or leave the yacht drifting unobserved. State a time or position trigger for stopping diagnosis and calling for assistance, rather than letting a checklist consume the entire margin.
Use the vessel's operating information for checks such as controls, fuel supply, electrical state, cooling and visible leaks. A stopped engine, an engine that will not crank, one that cranks but will not start and one that starts then overheats are different evidence states. Do not repeatedly crank, open a hot cooling system or enter a machinery space with fumes or fire risk merely because a generic list mentions it.
Before restart, check that nobody and no line is exposed to moving machinery or the propeller, that the gearbox/control state is understood and that restarting will not worsen flooding, fire, exhaust exposure or a grounding. A successful restart does not close the casualty until cooling, charging, leaks, propulsion and the revised passage plan are monitored.
| Observed state | Do not assume | Next evidence |
|---|---|---|
| Will not crank | That fuel is the cause | Controls, interlocks and electrical state under the manual |
| Cranks, will not start | That repeated cranking is harmless | Fuel/stop state and the manufacturer's procedure |
| Overheat or no cooling indication | That a restart is safe | Cooling path, leak and temperature under safe access |
| Restart succeeds | That the casualty is over | Cooling, charging, leaks, thrust and revised plan |
Set a diagnosis boundary
The engine stops while the yacht is being set towards the edge of a channel. Sail is available, but one crew member wants everyone below to work through the handbook.
1. Control
Establish steerage or another stable state and keep a dedicated lookout.
2. Measure
State position, depth, drift, traffic and the time or distance to the control boundary.
3. Diagnose
Give one competent person a bounded, vessel-specific check while the deck team preserves margin.
4. Escalate
Call early or execute the fallback at the named trigger, even if diagnosis is incomplete.
Sense check: A technically correct diagnosis made after the yacht has lost sea room is not a successful response.
Common mistake or limitation
- Beginning a long mechanical checklist before controlling drift and traffic.
- Using the whole crew for diagnosis and losing helm, lookout or communications capacity.
- Treating every failure mode as a fuel problem or every restart as permission to continue the original passage.
- Leaving the escalation point undefined until the situation has already become urgent.
Recap
- Control the yacht and measure the remaining margin before diagnosis.
- Match checks to the observed engine state and the vessel's own procedure.
- Protect people from machinery, heat, fumes, fire, flooding and propeller hazards before restart.
- A restart must be monitored and the passage plan reconsidered.
Optional quick check
Section 2 of 12
The engine stops near a channel edge and the yacht is visibly setting towards danger. What comes first?
Sources and factual review
Reviewed 20 August 2026 - Compass Revision editorial review.
Continue studying Special Situations Afloat
This public lesson is part of Revision Module 20. Full revision access adds the guided Learn, Practise and Test flow, flashcards and revision progress.