Section B – Boat on boat

RS CALL B1

Rule 11, On the Same Tack, Overlapped
Rule 15, Acquiring Right of Way

When a boat becomes overlapped to leeward from clear astern, the windward boat must act promptly to keep clear. If the windward boat reacts promptly but cannot keep clear, she has not been given sufficient room. If she takes unnecessary action that causes contact, she fails to keep clear as required.

Assumed Facts

Shortly before the start, W is sailing slowly on starboard tack. L, also on starboard, establishes an overlap to leeward from clear astern. Immediately afterwards, as W sheets in and luffs, her stern makes contact with the gunwale of L.

Question 1

Which rule, if any, has been broken?

Answer 1

When L becomes overlapped to leeward from clear astern, she acquires right of way under rule 11. As a result, L is initially required by rule 15 to give W room to keep clear. L's obligation under rule 15 is only temporary and W must respond promptly after the boats become overlapped. If W does so and there is contact with L, then L has failed to give room and breaks rule 15. If W could have kept clear, but either responds too slowly or not enough, or over-rotates, and causes contact with L then she breaks rule 11.

Question 2

W has no steerage way. Unable to luff, she maintains her course and promptly sheets in to accelerate. As she does so, she makes leeway and touches L. Does rule 15 apply in the same way?

Answer 2

Yes. If maintaining her course and accelerating is an appropriate response from W but, because of the characteristics of hull and keel, the boat initially makes leeway, then L is obliged under rule 15 initially to give W the room needed to keep clear.