I'll break it down a little bit further. See JimC's post above for the text of the rules.
Originally posted by Henmch
two dinghies approaching windward Mark on port tack in a force 2/3. Mark to be left to port. The boats are parallel to each other and the overlap existed before they entered the zone. |
Initially, boats were overlapped on the same tack when the first of them reached the zone: rule 18.2( b ) applied and B, the outside boat was required to give A, inside mark-room.
Originally posted by Henmch
Boat A is nearest the Mark about half a boat length away. Boat B is furthest from the Mark right on the edge of the zone.
Boat B tacks onto starboard when they can lay the Mark and calls starboard on A. |
Rule 18, in its entirety, and including rule 18.2( b ), ceases to apply when B passes head to wind, because boats are then on opposite tacks and the proper course of one of them, at the mark is to tack (rule 18.1( a )). While tacking, B is required to keep clear of A (rule 13)
Originally posted by Henmch
As soon as boat B is on their close hauled course |
B becomes the right of way boat (rule 10), initially required to give A room to keep clear ( rule 15)
Originally posted by Henmch
Boat A also tacks to starboard. |
A is still required to keep clear of B, now under rule 13.
From the instant A passes head to wind, both boats are on the same tack, they are no longer on opposite tacks and some part of rule 18 may apply (rule 18.1).
Rule 18.2 ( b ) can't apply because it got switched off when B tacked.
Rule 18.3 is a candidate: A is certainly tacking in the zone, but B was not 'on starboard tack since entering the zone': B came onto starboard tack after she had entered the zone: rule 18.3 does not apply.
So the only rule left is good old rule 18.2( a ), and it will apply, if and only if the boats become overlapped.
When A reaches her close hauled course, she is (presumably) clear ahead of B, and the right of way boat (rule 12), required to give B room to keep clear (rule 15).
Originally posted by Henmch
They can just make the Mark. Boat B has to go above close hauled course to avoid boat A although A was already on their close hauled course. |
While A is clear ahead, her obligation was initially to give B room to keep clear, which she did: there was ample space for B to luff above close hauled and keep clear.
If, B, having luffed above A, then becomes overlapped outside A, B will still be required to keep clear of A, now under rule 11, and also required to give A mark-room.
If B had dived, and hooked A to leeward, she would have gained right of way and mark-room as leeward inside boat.
Originally posted by Henmch
Any thoughts on who is in the right. I'm wondering if as boat boats tacked within the zone there is any variation in the rule. |
So, yes, B, passing head to wind inside the zone, switched rule 18.3 off.
|