The International Regulations for Preventing Collisions at Sea (COLREG 1972) apply to all vessels upon the high seas and connected waters. If you keep a bridge watch, these rules are your daily toolkit.
How the rules are organised
The Convention is split into five parts: General (Rules 1-3), Steering and Sailing (4-19), Lights and Shapes (20-31), Sound and Light Signals (32-37) and Exemptions (38). Part B, Steering and Sailing, is where most practical decisions come from.
Key rules in plain language
- Rule 5 - Look-out: Maintain a proper look-out by sight, hearing and all available means.
- Rule 6 - Safe speed: Choose a speed that lets you take proper and effective action in time.
- Rule 7 - Risk of collision: If in doubt, assume risk exists. A steady compass bearing on an approaching vessel means risk.
- Rule 8 - Action to avoid collision: Act early, make the alteration large enough to be readily apparent, and avoid a series of small changes.
- Rules 13-17 - Overtaking, head-on, crossing: They decide who gives way and who stands on, and what the stand-on vessel may do.
- Rule 19 - Restricted visibility: Safe speed, radar use and fog signals become critical.
Habits that help
- Treat radar and ARPA as aids, never as a replacement for a proper look-out.
- Make your intentions obvious. Do not rely on a VHF agreement in place of a rule-based manoeuvre.
- Call the Master early when in doubt. It is standard practice, not weakness.
This article is general information. Always consult the official IMO text for the current wording.