Mark rounding/windward boat

She had given me room, there was no collision, so that side of things was fine. I guess the question was, at what point did the rights of the leeward boat kick back in again after mark room was given. The answer, logically, was as soon as the inside boat was clear of the mark. As there was no tide, I would have been able to get clear (I think I tacked off, but too late) as soon as my transom was clear. In adverse tide, I would think that if being forced to tack off then pushes you back down onto the mark, you would still need mark room?

I got caught like this a few years ago after a less than perfect (though still within "seamanlike") rounding, when the leeward boat was able to force me to keep clear right after the mark. Luckily I did turns, as I lost the protest that I was still in the process of rounding. Up to that point, I'd not realized how quickly it all switches off. So long as we all understand how the rule works, then it isn't too bad, though in handicap racing there is both the problem of how high different boats point coming out of a mark, and how long it takes them to get to that point. If rounding outside a big, heavy boat, then they have the right to take their normal amount of time, I assume, to round and keep clear.

The rules really don't work as well for a mixed fleet.

It is interesting to stress test your proposition that an 18.2b continues until the entitled boat leaves the zone. Turn to team racing... which (mis)uses the same rules...

What your interpretation leads to  is that a boat that has passed the mark but not left the zone can gybe, return to the mark and once again claim mark room off other boats! Team racers would love to be able to do this - and they can but without any protection from rule 18!

The rule (18.2 and the definition of mark-room)  defines a corridor to the mark and around the mark. The dimensions of this corridor are variable according to the conditions, and may turn out to be bigger than originally expected. There may be disagreement as to the size of this corridor (which will be settled by the PC). Whilst taking mark-room the entitledboat has an obligation to manoeuvre in a seamanlike way, which may not be to the entitled boat's tactical advantage.

Once the entitled boat has sailed through this corridor and out the far end then they have been given mark-room as defined. The obligation of the room-giving boat ends and the entitled boats exoneration under rule 21 ends.

18.2 obligations can ALSO end because the entitled boat passes head to wind or leaves the zone.

However the entitlement to mark room does not necessarily apply until the entitled boat leaves the zone. It can end before the entitled boat leaves the zone (There was not an extraneous negative in my previous post).

Thanks guys for a very clear explanation as always. I was the helm of B and, as my initial reactions was doubt about who was in the right, I didn't shout. It was of course moderately windy and A was executing quite a tight turn and did not sheet in quickly. Actually I'm not sure he even noticed the minor contact.

I agree that Case 25 will get you there in this scenario, but note the following:

• you have to read the whole of Case 25 to apply it:  the headnote does not cover the content of the case very well;
• Case 25 relies on the distance IW was from the mark to conclude that she was not sailing within the mark-room to which she was entitled.

I suggest that there is a slightly different analysis available in this case.

• had left the mark astern (Definitions:  mark-room ( a ))
• had rounded the mark as necessary to sail the course (Definitions:  mark-room ( b ))
• had left the mark on the required side (Definitions:  mark-room, stem).

So, all the actions defined in mark-room have happened and been completed in the past.

IW sailed a hull length away from the mark on a course over 45 degrees below close-hauled and, as a result, took much more space than rule 18.2(b) entitled her to take.