Navigational Records and Passage Logbook Entries

Plan what will be recorded and how often before departure. For a small yacht, the method can be concise, but it should support the passage risks: time; position with source and quality; course or heading as relevant; speed or log reading; depth where useful; wind, pressure, weather and visibility; and significant 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 material events as well as the planned interval. There is no universal hourly rule in the reviewed IMO, RYA and MCA small-craft guidance; the plan should state the method and frequency needed for that risk.

A record supports dead reckoning and reconstruction if GNSS or a display fails, but it is not an independent fix unless the recorded evidence was independent. Write the source—such as GNSS, visual fix, transit, depth contour or radar range—and note unexplained disagreement rather than averaging it away. When the plan changes, record the decision and make sure the crew is following the revised version.