What the examiner is really probing
The examiner wants to know whether you understand the COLREGs as a living, applicable set of rules — not a document you once memorised. They will probe whether you can apply specific rules under pressure, articulate why a rule exists, and whether you appreciate the hierarchy of obligations across vessel types and conditions. A pass-standard answer demonstrates confident recall of rule content, correct use of terminology, and sound judgement in application. Simply reciting rules without demonstrating understanding of intent will not pass at OOW level.
The COLREGs — structure and scope
The International Regulations for Preventing Collisions at Sea 1972 (COLREGs), given effect in UK law, apply to all vessels on the high seas and connecting waters navigable by seagoing vessels. They are divided into five parts:
- Part A (Rules 1–3): Application, responsibility, definitions
- Part B (Rules 4–19): Steering and sailing rules — the core operational section, subdivided into conduct in any visibility (4–10), conduct in sight of one another (11–18), and conduct in restricted visibility (19)
- Part C (Rules 20–31): Lights and shapes
- Part D (Rules 32–37): Sound and light signals
- Part E (Rule 38): Exemptions
- Annexes I–IV: Technical details for lights, shapes, sound signals, and distress signals
Key principles the examiner will probe
Rule 2 — Responsibility: No rule excuses neglect of seamanship or departure from ordinary practice to avoid immediate danger. This is the COLREGs' safety valve; a candidate must know it exists and can override other rules.
Rule 5 — Lookout: By all available means, at all times. Not just visual — radar, AIS, hearing, VHF. Frequently tested as a scenario.
Rule 6 — Safe speed: Factors include visibility, traffic density, manoeuvrability, and the presence and effectiveness of radar. The standard is relative to the vessel and conditions, not an absolute figure.
Rule 8 — Action to avoid collision: Action must be positive, made in ample time, large enough to be apparent, and not result in another close-quarters situation.
Rule 16/17 — Give-way and stand-on: The stand-on vessel must maintain course and speed initially, but may (and ultimately must) take action once it becomes apparent that the give-way vessel is not acting sufficiently. Rule 17 is frequently misunderstood — knowing when the stand-on obligation shifts is a stretch-level topic.
Rule 19 — Restricted visibility: Applies to vessels not in sight. Safe speed, radar plotting, avoiding alteration to port for a vessel forward of the beam, and avoiding alteration towards a vessel abeam or abaft are the key obligations.
How to structure your spoken answer
State which rule you are applying before you explain it. Then give the content, followed immediately by how you would apply it in practice. If asked about intent, connect the rule back to Rule 2 or to good seamanship. Examiners are listening for logical sequencing and practical ownership of the rules — not a recitation.