COLREGs
The International Regulations for Preventing Collisions at Sea, rule by rule.
Topics in study order
- 1.COLREG Structure, Application and Definitions
How the Collision Regulations are built (Parts A–F and four Annexes), where and to whom they apply (Rules 1 and 2), and the Rule 3 definitions of vessel types, underway and making way. Every other rule leans on these terms, and examiners test them with traps.
12 cards
1 Nov 2026 - 2.Look-out and Safe Speed
COLREG Rule 5 (a proper look-out by sight, hearing and all available means) and Rule 6 (safe speed: six factors for every vessel, six more for vessels with radar), plus who may keep the look-out under STCW and MGN 315. Both rules apply in any visibility and come up in almost every MCA oral.
11 cards
1 Nov 2026 - 3.Risk of Collision and Action to Avoid Collision
COLREG Rule 7 (how to decide whether risk of collision exists: compass bearings, radar plotting, CPA and TCPA limits) and Rule 8 (what a proper avoiding action looks like, how to check it and when to resume course), with Rule 8(f) not impeding and MGN 324 on VHF. Examiners test both rules as live scenarios in almost every MCA oral.
12 cards
1 Nov 2026 - 4.Narrow Channels and Traffic Separation Schemes
COLREG Rule 9 (narrow channels: keep to starboard, who must not impede, overtaking and bend signals) and Rule 10 (traffic separation schemes: using, joining, crossing, inshore traffic zones, exemptions), with the MCA guidance in MGN 364 and the YG signal. Rule 10 is one of the most tested rules in the MCA oral.
12 cards
1 Nov 2026 - 5.Overtaking, Head-on and Crossing Situations
COLREG Rules 13, 14 and 15: how to recognise an overtaking, head-on or crossing situation by eye, by lights and on radar, who keeps out of the way and what each vessel must do. Examiners use these three situations in almost every MCA oral, often with a Rule 18 twist.
12 cards
1 Nov 2026 - 6.Give-way, Stand-on and Responsibilities between Vessels
COLREG Rules 16, 17 and 18 with Rule 8(f): what the give-way and stand-on vessels must do, the pecking order between NUC, RAM, CBD, fishing, sailing and power-driven vessels, and what "not to impede" really means. Examiners test SHALL–MAY–SHALL and the Rule 18 traps in almost every MCA oral.
12 cards
1 Nov 2026 - 7.Conduct in Restricted Visibility
COLREG Rule 19: how to handle vessels not in sight of one another in fog or other restricted visibility — safe speed, engines ready, avoiding action on radar alone, what to do on hearing a fog signal, and the MGN 315 bridge routine. A favourite MCA oral subject, because in fog there is no stand-on vessel.
12 cards
1 Nov 2026 - 8.Lights and Shapes: Basic Rules, Arcs and Ranges
COLREG Rules 20–22: when lights and shapes must be shown, the colour and arc of the masthead, side, stern, towing, all-round and flashing lights, and their minimum ranges by vessel length. It is the base for reading any vessel's lights at night, and a standard MCA oral question.
11 cards
1 Nov 2026 - 9.Lights and Shapes of Special Vessels and How to Read Them
The lights and day shapes of NUC, RAM, fishing, CBD, pilot, towing, sailing and WIG vessels (COLREG Rules 23–30), and a six-step script to read any set of lights: type, length, aspect, special circumstances, underway, making way. Examiners show you lights and ask what you see and what you do.
12 cards
1 Nov 2026 - 10.Manoeuvring, Warning and Fog Signals
COLREG Part D (Rules 32–36): whistle, bell and gong, the manoeuvring and warning signals for vessels in sight, and the Rule 35 fog signals for every type of vessel underway, at anchor or aground. Examiners can ask any fog signal, so learn them all.
12 cards
1 Nov 2026 - 11.Distress Signals
COLREG Rule 37 and Annex IV: every recognised distress signal, from red flares and the NC flags to DSC, EPIRB and SART, plus the Mayday, Pan-Pan and Sécurité priorities and the master's duty to assist. "Name the distress signals" is a classic oral question: know the full list.
12 cards
1 Nov 2026