Why Records Exist
The navigational log is the legal and operational record of a vessel's passage. In any investigation — collision, grounding, insurance claim, or flag state inspection — the deck log is the primary contemporaneous document. Gaps, erasures, or retrospective entries undermine its credibility and, by extension, the officer's credibility. MSN 1858 sets out the UK's requirements for vessels to which it applies; candidates must understand the principle that the record exists to demonstrate a proper watch was kept, not merely to satisfy a bureaucratic obligation.
What Must Be Recorded
On a yacht under 3000 GT operating on a coastal or ocean passage, the deck log should contain at minimum:
- Time, position and method of fix — GPS position alone is insufficient best practice; note the method (visual bearing, radar, GNSS, celestial) and, where appropriate, cross-checks used
- Course steered and speed — both ordered and actual where they differ
- Wind, sea state and visibility — at regular intervals and whenever conditions change materially
- Navigational hazards and traffic — any vessel manoeuvred for under COLREGS, or notable radar target
- Alterations of course or speed — time, reason and authority
- Equipment status — any failure, degradation, or return to service of navigational equipment
- Watch changes — officer on watch (OOW) name recorded at handover
- Any event with safety implications — near-miss, unusual sea condition, man overboard drill, distress traffic heard
Frequency and Discipline
Entries should be made at regular intervals — hourly as a minimum on passage — and immediately when a significant event occurs. The record must be contemporaneous; filling in the log from memory at watch end is poor practice and will not withstand scrutiny. Correct errors by a single line through the error, initial and date; never use correction fluid.
Chart Folios and Associated Records
The log does not stand alone. Worked charts, waypoint lists, pilot book annotations and passage plans form part of the navigational record suite. Charts used on passage should be retained for a reasonable period; an examiner may ask how long — the principle is that they support any subsequent investigation.
The OOW's Personal Responsibility
The OOW signs for their watch. An entry made under your signature carries your professional weight. A candidate must be able to explain not just what to record but why each entry matters — demonstrating to the examiner that they understand the log as evidence of a competent watch, not as a routine task.