COLREGs Explained for Day Skipper: Rules of the Road

The International Regulations for Preventing Collisions at Sea are commonly called COLREGs or IRPCS. Rule 1 applies them to all vessels on the high seas and waters connected with the high seas that are navigable by seagoing vessels. Harbours, rivers and other authorities can make conforming special rules, so charts, notices and harbour directions still need checking.

Part B has three distinct operating contexts. Rules 4–10 apply in any visibility; Rules 11–18 apply when vessels are in sight of one another; Rule 19 applies when vessels are not in sight in or near restricted visibility. That classification comes before deciding that an encounter is overtaking, head-on, crossing or a Rule 18 responsibility case.

Rule 2 prevents a mechanical 'right of way' reading. The owner, master and crew remain responsible for complying with the Rules and for precautions required by ordinary seamanship or special circumstances. A stand-on vessel has an obligation, not a licence to continue into collision, and a vessel that is not to be impeded still has collision-avoidance duties when risk develops.

For revision, use a repeatable loop: maintain the picture, determine risk, identify every applicable rule, take the required early action and observe until the vessels are finally past and clear. AIS labels or a single snapshot can assist orientation but do not decide the rule or replace visual and radar observations.