Module 16 - Pilotage
Advanced Scenario Check: Pilotage
What you will learn
Rebuild a night entrance plan when traffic, navigation evidence and vessel performance fail together before the final commitment point.
This scenario rehearses the Yachtmaster habit of stating what changed, protecting room, assigning checks and rebriefing. It is not a script for a live harbour entrance.
Your yacht is holding outside a fictional harbour at night. Port signals permit movement, but a ferry reports that it is departing. One leading light becomes obscured by background lighting. The chartplotter and tablet show the same position, but both depend on the yacht's GNSS receiver. The echo sounder is shallower than the planned trend, and the engine will not reach the revolutions used for the cross-stream timing calculation.
The movement signal does not make the entrance safe. Name each failed assumption: traffic occupies the commitment area; the leading-line observation is incomplete; the two electronic displays share a common source; depth does not match the model; and manoeuvring performance is reduced. Any one may justify delay. Together they remove the evidence and capability needed to open the gate.
Hold or abort outside the commitment point using the briefed safe route. Assign the lookout to identify the ferry and full leading-light sequence, the navigator to establish position and depth from independent evidence, and the helm or engineer to confirm controllable speed and engine response. Contact port control for current movement information without transferring the navigation decision to them.
Re-plan the stage with the actual tide, depth trend, vessel speed, stream exposure and traffic window. Rebrief the route, reports, minimum evidence and new escape trigger to the whole team. If a safe independent picture and controllable manoeuvre cannot be restored, do not enter. Written revision can rehearse this decision model, but it cannot demonstrate practical pilotage, command or Yachtmaster competence aboard.
Worked example
Give the first command brief when the ferry call, obscured leading light, shallow depth and reduced engine response appear together.
- 1State the decision: 'Entrance gate closed; remain in the briefed holding water.'
- 2State why: movement conflict, incomplete physical cue, common-source electronic positions, unexpected depth and reduced manoeuvring performance.
- 3Allocate checks with named reports: ferry position and intention, complete light identity, independent position/depth evidence, and controllable engine speed.
- 4Protect the escape route and tell port control the yacht is holding; do not accept permission as proof of navigational safety.
- 5Recalculate, re-plan and rebrief only after the actual evidence and vessel capability are understood.
Sense check: A defensible response creates time and room before solving the detail. Entering to 'get a better look' would consume both while the critical assumptions remain unproved.
| Changed condition | Why it matters | Safe response before commitment |
|---|---|---|
| Ferry departing | The traffic window and escape route have changed | Hold outside, establish the movement picture and rebrief |
| Leading light obscured | A planned physical cue is absent | Do not substitute route-line confidence; find independent evidence |
| Two GNSS displays agree | Both may share antenna, power, data or chart failure | Treat them as one source and seek a genuinely independent check |
| Depth shallower than expected | Position, tide, datum, sounder offset or seabed assumption may be wrong | Protect clearance, verify the model and retain the abort route |
| Reduced engine output | Timing, cross-stream set, steerage and escape performance have changed | Recalculate with actual capability or abandon the attempt |
Use challenge-and-confirm reports
The skipper asks whether the entrance can now be attempted after the ferry clears.
1. Lookout
Report the complete leading-light identity, alignment and traffic scene — or say plainly that identification remains uncertain.
2. Navigation
Report depth trend, the independently supported position and how the actual observations compare with the revised stage.
3. Helm and machinery
Report steerage and repeat the commanded speed or abort manoeuvre, including any remaining performance limitation.
4. Skipper
Challenge conflicts, confirm every gate condition and state the next trigger before opening the commitment gate.
Sense check: Silence, assumption or a repeated screen value is not confirmation. The report must identify the observation and its decision meaning.
Common mistake or limitation
- Waiting for every detail to be explained before ordering the hold lets the vessel drift through the decision gate.
- Voting between displays cannot resolve a common-source error; trace what each observation actually depends on.
- Port control supplies movement information and instructions, but the skipper retains responsibility for the safe navigation decision.
- This fictional exercise cannot prescribe a safe live course, speed, passing distance or harbour entry; use current local information and competent practical judgement aboard.
Recap
- State the changed assumptions before selecting a new action.
- Hold or abort before the final safe option disappears.
- Assign independent checks and require closed-loop reports.
- Recalculate, re-plan and rebrief the whole affected stage before entry.
Optional quick check
Section 12 of 12
The ferry has cleared, but depth still disagrees with the plan and engine output remains below the briefing assumption. What should open the entrance gate?
Sources and factual review
Reviewed 2 September 2026 - Compass Revision editorial review.
Continue studying Pilotage
This public lesson is part of Revision Module 16. Full revision access adds the guided Learn, Practise and Test flow, flashcards and revision progress.