The “ColRegs” & the International Regulations for Preventing Collisions at Sea

Sailors often refer to the “ColRegs”, short for Collision Regulations, as the rules of the road that govern, amongst other things, who has the right of way when boats meet on the water. When boats are racing, either in the same event or in separate events, the ColRegs are normally replaced by the Racing Rules of Sailing. However, the ColRegs always apply between boats if one or both are not racing. Also, sometimes the Sailing Instructions will specify that the rules of Part 2 are replaced by the ColRegs, typically for offshore events, or overnight events.

However, finding a definitive and authoritative source of the ColRegs is not without challenge.

The Racing Rules of Sailing refer to the International Regulations for Preventing Collisions at Sea (IRPCAS), as adopted by the International Maritime Organization (IMO).

So which is the correct term – ColRegs or IPRCAS? In Canada, the answer is both. The Collision Regulations, also available as a pdf, contain the International Regulations for Preventing Collisions at Sea, 1972 with Canadian Modifications in Schedule 1. Think of the IRPCAS as the RRS, and the Collision Regulations as the Sail Canada Rule Book with Canadian provisions.

For those looking for a quick comparison of the RRS vs IRPCAS, unfortunately neither Sail Canada nor World Sailing any longer publish such a summary. However, up until the 2009-2012 Rule Book, CYA, as Sail Canada was then known, did publish Appendix Q, a 5-page excerpt of the IRPCAS; that appendix remains an elusive but valuable reference, for those who aren’t inclined to read the 50+ pages of the IRPCAS.

So what changes under IRPCAS, vs the RRS? There is no Mark Room; an overtaking boat must keep clear, regardless of whether the boats are on different tacks; a right of way boat cannot luff or alter course, and more.

Page updated: 2020-06-25.

Update log

25 Jun: HM: Page created.

Page maintained by H. Morrin.