I am going to take a break from luffing rights which we discussed the last two months to go back to a topic that I discussed in November/December 2010 and January 2011. In the January 2011 issue I said ‘If you don’t want to follow the complex rules, I recommend a simple rule of thumb “don’t tack within three boat lengths of the mark”.’ I need to point out that this is a simple rule of thumb, not an enforceable rule. While it is simpler and safer not to tack within three boat lengths of the mark, there are several legal ways to tack within three boat lengths of the mark. I have heard recently that my articles were being quoted as evidence that this was illegal which it is not.

(click on the diagram to see a larger cleaner version)
In the diagram the Yellow boat has clearly overstood the mark and is coming in below closehauled on starboard tack. The Blue boat approaches the mark on port tack below the port tack lay line. When she gets to the starboard tack layline, she tacks and completes her tack within the zone at position 4. Yellow has time to avoid her but chooses not to yelling “I am holding my course you have no rights.” Blue does in fact have rights. She is a leeward boat and Yellow is a windward boat. Blue has a restriction under rule 18.3(a) not to cause Yellow to have to sail above close-hauled to avoid her. Yellow is required to head up to avoid Blue and as long as she doesn’t have to go above close-hauled Blue is quite legal. This can be difficult for Blue to prove if it is close, since Yellow has a much clearer picture of her own course, but Yellow really should avoid Blue and in doing so prove that she had to sail above close-hauled. In the diagram she does not have to sail above close-hauled.
13 WHILE TACKING
After a boat passes head to wind, she shall keep clear of other boats until she is on a close-hauled course. During that time rules 10, 11 and 12 do not apply. If two boats are subject to this rule at the same time, the one on the other’s port side or the one astern shall keep clear.
18.3 Tacking When Approaching a Mark
If two boats were approaching a mark on opposite tacks and one of them changes tack, and as a result is subject to rule 13 in the zone when the other is fetching the mark, rule 18.2 does not thereafter apply. The boat that changed tack
(a) shall not cause the other boat to sail above close-hauled to avoid her or prevent the other boat from passing the mark on the required side, and
(b) shall give mark-room if the other boat becomes overlapped inside her.

(click on the diagram to see a larger cleaner version)
In the second diagram the Red boat is ahead of the Green boat when she completes her tack (at position 4) and remains ahead as she rounds the mark at position 5. Green may have had to avoid her at position 6 but clearly does not go above close-hauled to do it so Red has not broken rule 18.2(a). Their next leg is a reach to the offset mark. At position 7 they have both passed the mark. Red is the leeward right-of-way boat and as we have discussed the last couple of months she has “luffing rights” since the overlap was established by Green to windward from clear astern. Red executed a quite legal tack within three boat lengths of the mark and now has right-of-way.
A few people have asked if the windward mark and the offset mark are really part of the same mark. The answer is no. They are two separate marks with a short leg in between. There will be a new mark-room situation at the offset mark.
© Copyright 2012 Andrew Alberti