Defending your lane
The situation
A boat is creeping up to windward, trying to roll over Priya. Priya, the leeward boat, luffs gently to slow the windward boat and protect her wind.
The question
How far up can Priya luff to defend her lane?
The ruling
Priya (leeward) has right of way and the windward boat must keep clear (rule 11). How high she may go depends on how the overlap began: if the windward boat established the overlap from clear astern within two hull lengths, rule 17 limits Priya to her proper course — she can't luff above it. If the overlap formed some other way (for example the windward boat tacked in), there's no proper-course limit and she may luff head to wind. Either way, rule 16.1 means she must change course slowly enough to give room to keep clear.
Leeward defends — but if the windward boat came from clear astern within two lengths, rule 17 caps you at proper course.
Opens the situation on the boat-length grid — scrub it and see exactly how the boats meet. Free, no account needed.
Rules cited
- Rule 11 — On the Same Tack, Overlapped
- Rule 17 — On the Same Tack; Proper Course
- Rule 16.1 — Changing Course
See the underlying rule: Rule 11 — On the Same Tack, Overlapped.