AS was clear ahead of BP when she reached the zone. Between position 1 and 2, AS, a hull length to leeward and a hull length ahead of BP, tacked as soon as she reached the starboard-tack lay line. Almost immediately she was hit and damaged by BP travelling at about ten knots. The protest committee disqualified AS for breaking rule 15. It also disqualified BP under rule 2, pointing out that she knew AS was going to tack but did nothing to avoid a collision. BP appealed, asserting that she was not obligated to anticipate an illegal tack.

After AS reached the zone, BP was required by rule 12 to keep clear of her and by rule 18.2(b) to give her mark-room. Both these obligations ended when AS passed head to wind (see rules 18.1(a) and 18.2(c)). When AS passed head to wind, BP became the right-of-way boat under rule 13 and held right of way until AS assumed a close-hauled course on starboard tack. At that moment AS, having just acquired right of way under rule 10, was required by rule 15 to give BP room to keep clear.

The collision occurred almost immediately after AS assumed a close-hauled course on starboard tack. Therefore, BP needed to take avoiding action before AS had borne away to close-hauled course. At that time BP had right of way under rule 13.

It is a principle of the right-of-way rules, as stated in rule 15, that a boat that becomes obligated to keep clear by an action of another boat is entitled to sufficient time and space to respond. When AS acquired right of way under rule 10, she did not give BP room to keep clear and broke rule 15. Finally, AS broke rule 14 because she could have avoided the contact by turning back onto port tack after she passed head to wind.

BP took no action to avoid the collision, but what could she have done? Rule 14 clearly states that a right-of-way boat need not act to avoid contact until it is clear that the other boat is not keeping clear. Given her speed and the distance involved after it became clear that AS was not keeping clear, BP had perhaps one to two seconds to decide what to do and then do it. While it was obvious that AS would eventually tack to round the mark, no rule required BP to anticipate that AS would break a rule.

BP did break rule 10, but she was exonerated for that breach by either rule 43.1(a) or rule 43.1(b). BP did not break rule 14 because it was not reasonably possible for her to have avoided the collision after AS broke rule 13. BP did not violate any principle of sportsmanship or fair play and, therefore, did not break rule 2.

BP's appeal is upheld. She is to be reinstated. AS remains disqualified.

USA 1971/140