International Regulations for Preventing Collisions at Sea — steering rules, lights, and shapes.
Steering and sailing rules (Rules 5, 7, 8, 9, 10, 12–19)General rules including Rule 2 (Responsibility)Rule 19 (Restricted Visibility) in detailNavigation lights and day shapes
14 guided lessons · 20 practice questions · 21 flashcards
3 outcomes · self-guided revision
Explain international Regulations for Preventing Collisions at Sea — steering rules, lights, and shapes.
Apply Steering and sailing rules (Rules 5, 7, 8, 9, 10, 12–19) to a realistic onboard situation.
Recall the core check: cOLREGs apply to ALL vessels on navigable waters.
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What Are the COLREGs?
The International Regulations for Preventing Collisions at Sea (COLREGs, also known as IRPCS) are the 'rules of the road' at sea. They apply to all vessels on the high seas and connected...
COLREGs apply to ALL vessels on navigable waters
Part B (Steering and Sailing Rules) requires full knowledge
Rule 2 underpins every other rule. It states that nothing in the COLREGs shall exonerate any vessel, owner, master, or crew from the consequences of neglecting the rules, or neglecting an...
No vessel is exempt from the consequences of neglecting the rules
Ordinary practice of seamen must always be followed
Every vessel shall at all times maintain a proper look-out by sight AND hearing, as well as by all available means (including radar), so as to make a full appraisal of the situation and t...
Look-out by sight AND hearing at all times
Use all available means appropriate to the circumstances; radar where fitted and operational, with AIS only as a supplement
Any action taken to avoid collision must be positive, made in ample time, and large enough to be readily apparent to the other vessel. Small, indecisive course changes are dangerous — the...
Rule 12 (Sailing vessels): When two sailing vessels meet, the vessel on port tack gives way to the vessel on starboard tack. If both are on the same tack, the windward vessel gives way. I...
Sailing vessels: port tack gives way to starboard tack
Overtaking vessel ALWAYS gives way (overrides other rules)
Rule 18 sets responsibilities between vessel types and statuses. It is a practical guide to who should keep clear in normal sighted encounters, not an absolute right-of-way ladder.
Rule 18 sets keep-clear duties by vessel status and manoeuvrability
Avoid impeding vessels limited by channel, fairway, or draught constraints
Rule 9 (Narrow Channels): Keep to the starboard side. Vessels under 20m or sailing vessels must not impede vessels that can only navigate within the channel. Do not cross a narrow channel...
Narrow channels: keep to starboard side
Small vessels must not impede vessels confined to the channel
Power-driven vessels display: masthead light(s) (white, 225°), sidelights (red port, green starboard, each 112.5°), and a stern light (white, 135°). Vessels 50m or more show two masthead...
Day shapes are black shapes hoisted where they can best be seen during daylight to indicate a vessel's status or activity. They supplement or replace lights during the day and are require...
Rule 19 applies to vessels not in sight of one another when navigating in or near an area of restricted visibility (fog, heavy rain, snow, etc.). It replaces Rules 12–18 when vessels cann...
Applies when vessels are NOT in sight of one another
COLREGs at Yachtmaster level is not just recall. The answer has to show command judgement, evidence quality, margin, and a fallback if the first plan stops being safe.
State the evidence you trust and the evidence you distrust.
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