Windward mark to be left to port. Boat A approaches on port tack, perhaps 1 boat length below the lay line. Boat B is clear astern but sailing fast and free as she has slightly overstood the mark.
You seem to be saying that A was clear ahead when she reached the zone, and 1 boat length below the port tack layline.
You seem to have a 'mental movie' of the incident which I can't quite appreciate from your description.
If A was already in the zone when she tacked onto starboard, (new) rule 18.3 will not apply.
Rule 18.3 now only applies when the outside windward boat has been on starboard tack since entering the zone. For that to happen, A would have needed to be between 2 and 3 boatlengths below the layline, and have slightly overstood before tacking from port onto starboard.
So, from the time that A passes head to wind and rule 18 ceases to apply for the first time, no part of rule 18 will apply until B also passes head to wind and comes onto the same tack., at which time rule 18.2( a ) begins to apply, and the inside overlapped boat is entitled to mark-room and rule 21 exoneration.
A passes the mark, hails "TACKING!" and tacks onto starboard.
As usual, I can't see how yelling about it helps matters. Maybe A thought that somehow yelling was going to get her some sort of consideration if she broke rule 13.
Maybe A should have been thinking about http://www.racingrulesofsailing.org/cases/772?page=2" rel="nofollow - Case 15 .
Boat B waits until A's tack is complete,
If B 'waited' until A's tack was complete (presumably you mean A had reached her close hauled course), then, isn't that saying that B took avoiding action while A was tacking, and so A was not keeping clear of B and broke rule 13?
at which point the boats are bow on bow and fairly close.
How close was 'fairly close'? If she was 1 BL away and aiming bow to bow, then when both boat's advance 1 BL, that's B looking at A's aft quarter, with only a very slight bear away needed to keep clear. Questions that a protest committee would need to answer would be:
- What was the actual space between boats?
- From the instant that A reached her close hauled course, was there enough space for B to have borne away to keep clear?
- If contact had occurred, when was it 'clear' that B was not keeping clear ( http://www.racingrulesofsailing.org/cases/713?page=9" rel="nofollow - Case 87 )
B tacks, rounding the mark as she does so,
I can't see how this can all fit into the space you have described. If A was 1 BL below the layline then tacked and reached a close hauled course, her bow or beam must then have been about at the mark, so how was there any space for B to tack and round the mark inside her?
Maybe there was a little more space all round.
but A has to luff to avoid whilst she is doing so
Well, if A needed to luff to avoid B, before B had reached her close hauled course, than B, while tacking has failed to keep clear of A and broken rule 13.
But if B passed head to wind, then, from that time, B is same tack, overlapped inside A and entitled to mark-room (rule 18.2( a ), and rule 21 exoneration if she breaks rule 13.
Note: there is some debate about this interpretation: RYA seems to think that in this circumstance B is taking 'room to tack' to which she is not entitled (see Definition of mark-room), and does not get exoneration.
See the lengthy discussion on racingrulesofsailing http://www.racingrulesofsailing.org/posts/32-rule-18-3-and-starboard-roundings" rel="nofollow - here
A fair bit of shouting ensued but without including the "P" word so no further action was taken.
My crew felt we (B) were on dodgy ground due to 18.3, whereas my feeling was that no rule was broken, because...
Initially A was entitled to mark room (18.2b)
Yes
Once A passed head to wind she was no longer entitled to mark room (18.2c)
Yes, and rule 18.1( b ).
A gained right of way only when she completed her tack reached her close hauled course(10)
Yes
B now took avoiding action kept clear by tacking, but A must initially give her room to keep clear, which she did (15)
OK
As B tacked she also rounded the mark, so rule 18 no longer applies at all
The rule 18 entitlement arises under rule 18.2( a ). It is not switched off by rule 18.2( d ). It switches off when B ceases to be overlapped inside.
and B is now right of way boat (11). At this point rule 15 does not apply to B as she gained right of way by B's actions.
No, B gained right of way when she reached her close hauled course. This was not because of any action by A (the other boat), so rule 15 applies
But reading 18.3 in isolation implies that B is in the wrong because she tacked in the zone to avoid a boat that was laying the mark, who then had to luff above close-hauled to avoid her.
Would have been under the 2013 rules, but not now: A has to be on starboard since entering the zone.
I feel like 18.3 switches off in this circumstance because of A gaining right of way so late, but I can't come up with a reason why!
Under the 2017 rules, 18.3 does not apply at all, unless A passes head to wind outside the zone.
Under the 2013 rules 18.3 applied if A passed head to wind first, no matter where.
But there's nothing to protect A from rule 13 while she's between head to wind and close hauled, while B is on port tack.
In a practical sense the only way B could have complied with 18.3 would have been to anticipate A's tack onto starboard and begun taking avoiding action by bearing away below her whilst they were both still on port.
And protested A for breaking rule 13.
This seems wrong!
What's wrong with that.