Originally posted by jeffers
In this situation Port/Starboard applies until the closest boat enters the zone at which point Rule 18 takes over and each boat then had different obligations which override port starboard.
Not quite right. Since 2009, Right of Way rules (Port/Starboard, W/L, Ahead/Astern, and Tacking) continue to apply all the way round the mark, as well as mark-room, with a boat that breaks a right of way rule while sailing within the mark-room to which she is entitled exonerated under rule 21.
So as soon as boat B enters the zone rule 18 applies.
So B, overlapped outside, on port tack, must keep clear of A, on starboard, and also give A mark-room.
The outside boat is required to give Mark-Room which is defined as below:
Mark-Room Room for a boat to leave a mark on the required side. Also, (a) room to sail to the mark when her proper course is to sail close to it, and (b) room to round the mark as necessary to sail the course. However, mark-room for a boat does not include room to tack unless she is overlapped inside and to windward of the boat required to give mark-room and she would be fetching the mark after her tack. |
B does have to allow room for A to gybe (rule 18.4)
Rule 18.4 is not the source of A's entitlement to room to gybe: that comes directly from the definition of mark-room 'room to round the mark as necessary to sail the course'.
Rule 18.4 imposes a limitation on A and obliges A gybe once her proper course is to do so.
but A (as I understand it) is not allowed to sail out wide and do a 'tactical rounding' they must sail directly towards the mark
Generally, a right of way boat with mark-room must be given room to make a 'tactical rounding' (US Appeal 20), in wide, out tight, changing course no faster than is the optimum for the boat, etc. It is a give way boat with mark-room that can be manoeuvered against by a right of way boat to make a 'seamanlike rounding', as fast and as close as is possible in a seamanlike way.
Rule 18.4 doesn't limit A's ability to make a tactical rounding because sailing beyond the point where her proper course was to gybe would not be 'tactical'.
If A sailed wide and gybed at the point under rule 18.4 where she was obliged to, if she was then overlapped to windward of B, she would be obliged to keep clear by luffing up as far as her 'seamanlike' course 'to round the mark as necessary to sail the course', after which point, she would be sailing within the mark-room to which she was entitled, and, if she did not keep clear of B would be exonerated under rule 21 and B would fail to give her the mark-room to which she was entitled.
and is then entitled to proper course at the mark.
'Proper course at the mark' was the 2009 rules formulation. It has been removed and the definition of mark-room is now as you have quoted it. She is entitled to 'room to round the mark as necessary to sail the course'.
A certainly should not have been calling starboard once B had entered the zone.
I agree that nobody should have been 'calling' things to one another. Both should have been concentrating on sailing their boats, not having chatty conversations. Except for a hail of 'protest' and a hail for room at an obstruction under rule 20, 'calls' or 'hails' have no effect on boat's entitlements under the rules.
In this case, if A had hailed 'Starboard' at any time while she was on starboard tack and B was on port, she would be doing absolutely nothing wrong: she would have right of way, with no limitations on her (at least until the rule 18.4 point), and B would be required to keep clear (as well as giving mark-room). |