The 2017 - 2020 Racing Rules of Sailing III

This month, we continue with our review of the changes in the latest rule book, 2017-2020. The hard copy of the new book is now available from Sail Canada. I hope that local stores will have it soon. It is also available on the web from the World Sailing site. This month, I will continue our look at mark roundings, this time looking at rule 18.3 “Tacking in the Zone”. Rule 18.3 has always been the part of rule 18 that is most difficult to explain. When it was first introduced, in 1997, I summarized it by saying “Don’t tack within the zone unless you have read the rule at least three times.” The new version is not much easier to understand. It does eliminate some unusual cases and limits the rule to its originally intended purpose.

Rule 18.3 is designed to limit the actions of port-tack boats with respect to approaching starboard-tack boats when the starboard-tackers are on the layline of a mark that is to be left to port. If the port-tack boat can tack in front a starboard-tack boat and stay far enough ahead so that she does not interfere with it, then the port-tack boat is okay. If not, then the port-tack boat is probably in trouble.

One problem with the earlier versions of rule 18.3 is that it applied to marks to be left to starboard (a very unusual situation in fleet racing, but one that does occur with fixed-mark courses). In this case, it was the right-of-way, inside starboard-tack boat who was restricted in her tacking. This led to starboard-tack boats sailing past the layline and causing more chaos before they tacked. In the 2017-2020 rules, rule 18.3 no longer applies at marks to be left to starboard.

A second problem with the earlier versions of rule 18.3 is that it applied between two boats, both of whom had tacked within the zone. In that situation, it was very important to know who passed head to wind first. This was often very difficult to determine. In the 2017-2020 rules, rule 18.3 does not apply between to boats who approach on the same tack. .  



18.3 Tacking in the Zone

If a boat in the zone passes head to wind and is then on the same tack as a boat that is fetching the mark, rule 18.2 does not thereafter apply between them. The boat that changed tack

(a) shall not cause the other boat to sail above close-hauled to avoid contact 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.

If a boat in the zone of a mark to be left to port passes head to wind from port to starboard tack and is then fetching the mark, she shall not cause a boat that has been on starboard tack since entering the zone to sail above close-hauled to avoid contact and she shall give mark-room if that boat becomes overlapped inside her. When this rule applies between boats, rule 18.2 does not apply between them.


Rule 18.3 continues to apply in the circumstance that we most commonly use it and despite some different words, it means the same thing.

Purple approaches the weather mark on port tack. Green and Yellow are both fetching the mark on starboard tack. After Purple passes head to wind from port tack to starboard tack, she is fetching the mark. Yellow at position 5 becomes overlapped inside Purple, so Purple has to give Yellow mark-room. She appears to give Yellow room, but heads up to avoid her. In doing so she forces Green to head above close-hauled and breaks the other part of the rule.

In summary, rule 18.3 is the same as it was before, in the most common situations. In two much less common situations, a mark left to starboard, and two boats approaching on the same tack and both tacking, it no longer applies. It remains just as important now to read the rule carefully; it is at least as important also to think about it.

© Copyright 2017 Andrew Alberti