A boat is not required to anticipate that another boat will break a rule.
When a boat acquires right of way as a result of her own actions, the other
boat is entitled to room to keep clear.
Summary of the Facts
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.
Decision
BP’s appeal is upheld. She is to be reinstated. After AS reached
the zone, BP was required to keep clear of AS and give her mark-room under
rule 18.2(b). Both these obligations ended when AS passed head to wind
because the boats were then on opposite tacks and on a beat to windward.
When AS passed through 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. BP took
no action to avoid a collision, but what could she have done? Given her
speed and the distance involved, she had perhaps one to two seconds to
decide what to do and then do it. It is a long-established 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 for response. Also, while it was obvious that AS would have to tack
to round the mark, BP was under no obligation to anticipate that AS would
break rule 15, or indeed any other rule. BP broke neither rule 2 nor rule
14.