Module 14 - Passage Planning
Navigational Records
What you will learn
Keep a risk-based record that supports monitoring, distinguishes position sources and makes material passage changes understandable to the next watch.
A useful log records evidence and decisions when they matter. It does not create accuracy by itself, and one fixed interval is not suitable for every passage leg.
Plan what will be recorded and how often. A concise yacht log can include time; position with source and quality; course, heading or track labelled correctly; speed or log reading; relevant depth; wind, pressure, weather and visibility; and material changes in sail, engine, crew, communications, route, timing or destination.
Choose intervals from the consequences of losing track. Stable open water may justify a longer regular interval than pilotage, restricted visibility, nearby hazards or a tidal gate. Record at significant events as well. There is no universal hourly rule in the reviewed IMO, RYA and MCA small-craft guidance.
A record supports dead reckoning and reconstruction after electronic failure, but a recorded GNSS coordinate is not an independent fix. Name the source—GNSS, visual fix, transit, depth-supported DR or radar range—and record unexplained disagreement rather than averaging it away. A material plan amendment belongs in the log and crew brief when it is made.
Worked example
Fictional log extract approaching the overnight passage's decision point. It records evidence, comparison and action rather than a decorative list of coordinates.
- 11610: departed; GNSS position cross-checked with harbour transit; log 0.0; SW 4; 1014 hPa; arrival plan 0600 for 0700 gate.
- 22135: visual fix agrees with DR; log 30.1; headland trigger not met; refuge and crew state remain acceptable.
- 30215: GNSS and depth-supported DR disagree; reduced speed and preserved safe water while obtaining another independent fix.
- 40230: worsening visibility and revised gate ETA 0640; recorded diversion decision, revised route and crew brief before the refuge deadline.
Sense check: The extract shows why the plan changed. A bare list of positions would not show the lost margin, conflicting evidence or accepted response.
| Record | Example detail | Decision value |
|---|---|---|
| Time and position | Source, quality and disagreement | Reconstructs progress and uncertainty |
| Course, speed or log | Label heading, track or course correctly | Supports DR, ETA and change detection |
| Weather and depth | Wind, pressure, visibility, sea and soundings | Tests forecast and safe-water assumptions |
| Significant event | Sail, engine, crew, communications or equipment change | Shows why capability or workload changed |
| Plan amendment | Decision, reason, revised route and briefing | Keeps execution aligned with the accepted plan |
Change the record with the risk
The passage moves from open water into a narrow, tide-constrained approach with background lights and a nearby shoal.
1. Open water
Use the planned regular interval and record material weather, route, equipment or crew changes.
2. Before approach
Record a reliable starting position, current ETA, depth expectation and abort limit.
3. Inside pilotage
Increase frequency and use the visual, depth and electronic checks named in the pilotage plan.
4. After change
Record the revised decision and brief so the log, route and crew understanding remain aligned.
Sense check: The interval changes because the pace and consequence of error change, not because a universal clock rule applies.
Common mistake or limitation
- Writing positions without their source, making GNSS, DR and an independent fix look equally reliable.
- Using one interval through open water and constrained pilotage regardless of how quickly danger or uncertainty can develop.
- Recording a diversion after the event but not updating the working plan and watch brief at the decision time.
Recap
- Choose log content and frequency for the risk of each leg.
- Record the source and quality of position evidence, not just a coordinate.
- Log and brief material changes so the record supports the current passage.
Optional quick check
Section 7 of 12
What is the best logging response on entering constrained pilotage?
Sources and factual review
Reviewed 2 September 2026 - Compass Revision editorial review.
Connect records to passage monitoring
Good records support the monitor stage of passage planning and make navigation decisions easier to review.