Module 16 - Pilotage
Night Pilotage
What you will learn
Identify night aids from the complete charted description, manage background-light ambiguity and execute a reduced-workload plan with earlier uncertainty gates.
Darkness removes many daytime references and can make a bright but wrong light look persuasive. Night pilotage therefore relies on a pre-briefed sequence, complete light identities and conservative confirmation before each commitment.
Prepare from the current chart, Sailing Directions, List of Lights, notices and local instructions. For every critical light record the complete repeating characteristic and period, colour, charted position and structure, then compare the expected sequence and relative bearing with the real scene. Brightness or colour alone is weak evidence because background lights, atmospheric conditions and range can mislead.
A sector light displays different colours and/or rhythms over charted arcs. It may guide a fairway, mark a turn, indicate a junction or warn of a hazard; no universal rule makes every white sector safe for every route. Boundaries can appear less definite in practice and IALA allows oscillating boundaries, so use the charted geometry, a second cue and an early response rather than steering along a colour edge.
Reduce avoidable workload before commitment: dim displays and cockpit lighting while keeping instruments readable, preserve a dedicated lookout, call light identities using the full rhythm, and avoid sending the skipper below to search long text. Replace unlit daytime cues with robust night alternatives, reduce speed enough to observe a full period and keep the holding or abort gate outside the confused-light area.
Worked example
The plan expects a charted white Fl(3) 10s light. The lookout observes three flashes and starts a stopwatch at the first flash of the next group.
- 1Observe the whole repeating group rather than counting three flashes once.
- 2Measure from the same point in one cycle to the same point in the next; the complete period should be about 10 seconds.
- 3Confirm colour, charted bearing or position, structure and expected sequence before using the light as the next gate.
Sense check: Three flashes without the ten-second cycle and positional match could belong to another light; timing strengthens identity but does not prove it alone.
| Night question | Evidence to call | Unsafe shortcut |
|---|---|---|
| Which light is this? | Full rhythm and period, colour, position and structure | It is the brightest red light |
| Are we in the intended sector? | Charted arc, colour or rhythm, bearing and second cue | White always means safe |
| Can we commit? | Expected sequence, depth, traffic and hold/abort gate | The next waypoint is ahead |
Handle a sector-colour change without guessing
The intended approach is within a charted white sector. The light appears red after the yacht is set sideways by the stream.
1. Use the charted meaning
Confirm which red arc has been entered and what hazard or limit it represents on this approach.
2. Protect the margin
Apply the pre-briefed course or speed response before tracking along the sector boundary.
3. Confirm recovery
Use bearing, depth, position and the next expected cue rather than colour alone to verify the yacht is back in the planned water.
Sense check: The useful response comes from the charted arc and route geometry, not from a memorised belief that red always lies on one side.
Common mistake or limitation
- Colour or brightness alone does not positively identify a light against a busy shore background.
- Sector boundaries and meanings are chart-specific; treating every white arc as universally safe can put the yacht on the wrong approach.
Recap
- Prepare complete light identities and their expected sequence before darkness increases workload.
- Use sector geometry from the chart and corroborate every critical cue.
- Slow, hold or abort early when the night scene does not match the plan.
Optional quick check
Section 9 of 10
A light matches the expected colour but its period and bearing do not. What should the skipper do?
Sources and factual review
Reviewed 2 September 2026 - Coastal Skipper Revision.
Continue studying Pilotage
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