In the last article, I discussed the changes to rules 17 and 20. This time, I am going to discuss mark-room or rule 18. If you look at a marked-up version of the changes to Rule 18, it will appear that almost the entire rule has been rewritten. Most of the changes involve sequence, formatting and numbering.

Mark-room or rule 18 is one of the longest rules in the book. There are so many different ways that boats can interact when they come together at marks, that this rule has always been a challenge for the rule writers. A group got together about four years, ago with the idea of simplifying this rule. The eventual changes were not as significant as they first proposed.

The basic structure of rule 18 is in four parts. 18.1 discusses when rule 18 applies and when it doesn’t. Rule 18.2 is the core, which describes who must give mark-room. Rule 18.3 covers the situation where one boat, but not both, have to tack within the zone. Rule 18.4 is about gybing in the zone. This structure did not change. 18.2 was completely reordered. The most common situation was 18.2(b). It is now 18.2(a). The old 18.2(a) which sounded like the basic rule, but turns out to rarely apply, has moved to 18.2(c). The other parts have been moved around them. None of this changes the meaning.



 

A significant change in rule 18.2 is shown in the diagram. Yellow is clear ahead of Blue. Yellow is flying an asymmetrical spinnaker staying high to keep her speed up. Blue’s hull gets to the zone (three hull lengths from the mark) before Yellow. Under the 2021-2024 rules, Yellow as the boat that was clear ahead, when one of them reached the zone, would be entitled to mark-room. With the changes in 2025, Rule 18.2(a)(2) says when the boats are not overlapped, the boat that gets to the zone first, gets mark-room. This means that Blue gets mark-room. This may be tricky to judge. If Yellow was about a hull length further to leeward, she would have reached the zone first and would have been entitled to mark-room. Yellow is actually in a poor position to see how far from the mark she is. Yellow can see how far Blue is from the mark and Blue can see how far from the mark Yellow is.

The size of the zone and when boats enter it are based on hulls and hull lengths. Overlaps are based on equipment in normal position, so the spinnaker pole counts for overlaps but not for entering the zone. This is not a change.


 

In the second diagram we see a more complicated situation. Red and Green are both approaching a windward mark on port tack. At position 1, when Red gets to the zone they are overlapped. Red is entitled to mark-room. At some point between position 5 and 6 both boats tack to starboard. At position 6, both boats are on starboard tack and are both fetching the mark. It does not appear that Red has completed her tack, but she will soon after position 6. Under the 2021-2024 rules there was some disagreement amongst judges about how the rules applied. The 2025-2028 rules clarify it. The first part of rule 18.3 applies. It says “if a boat”, in this case Red, “passes head to wind from port to starboard tack in the zone of a mark to be left to port”, all of which applies to Red, “rule 18.2 does not apply between her and another boat on Starboard tack”, in this case Green, “that is fetching the mark”, which Green is. So, we know that none of rule 18.2 applies. The first part of the next sentence in 18.3 says “If the other boat has been on starboard tack since entering the zone” the rest of rule 18.3 applies. Since Green was not on starboard tack since entering the zone, the rest of the rule 18.3 doesn’t apply. There is nothing left that is relevant in rule 18, so none of rule 18 has any effect. This is a basic right-of-way situation in between Green and Red. In this case until Red completes her tack, Green has right-of-way based on rule 13 and after Red completes her tack, she has right-of-way based on rule 11. The rules are as if the mark was not there.

I have a final comment to add. I posted an article in January about the changes to Rule 14. I still believe what I wrote, but I will say that there are several people whose opinions I respect about the rules who disagree with me. We will have to wait and see if World Sailing provides some clarification about the meaning of “to cause.”

RRS 2025-2028 (text underlined is new)

18.2 Giving Mark-Room

(a) When the first of two boats reaches the zone,

(1) if the boats are overlapped, the outside boat at that moment shall give the inside boat mark-room;

(2) if the boats are not overlapped, the boat that has not reached the zone at that moment shall give the other boat mark-room.

When a boat is required to give mark-room by this rule, she shall continue to do so for as long as this rule applies, even if later an overlap is broken or a new overlap begins.

(b) Rule 18.2(a) no longer applies if the boat entitled to mark-room passes head to wind or leaves the zone.

(c) When rule 18.2(a) does not apply and the boats are overlapped, the outside boat shall give the inside boat mark-room.

(d) If a boat obtained an inside overlap from clear astern or by tacking to windward of the other boat and, from the time the overlap began, the outside boat has been unable to give mark-room, rules 18.2(a) and 18.2(c) do not apply between them.

(e) If there is reasonable doubt that a boat obtained or broke an overlap in time, it shall be presumed that she did not.

18.3 Tacking in the Zone

If a boat passes head to wind from port to starboard tack in the zone of a mark to be left to port, rule 18.2 does not apply between her and another boat on starboard tack that is fetching the mark. If the other boat has been on starboard tack since entering the zone, the boat that passed head to wind

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

(b) shall give mark-room if the other boat becomes overlapped inside her.

 

RRS 2021-2024 (text struckthrough has been deleted)

18.2 Giving Mark-Room

(a) When boats are overlapped the outside boat shall give the inside boat mark-room, unless rule 18.2(b) applies.

(b) If boats are overlapped when the first of them reaches the zone, the outside boat at that moment shall thereafter give the inside boat mark-room. If a boat is clear ahead when she reaches the zone, the boat clear astern at that moment shall thereafter give her mark-room.

(c) When a boat is required to give mark-room by rule 18.2(b),

(1) she shall continue to do so even if later an overlap is broken or a new overlap begins;

(2) if she becomes overlapped inside the boat entitled to mark-room, she shall also give that boat room to sail her proper course while they remain overlapped.

(d) Rules 18.2(b) and (c) cease to apply if the boat entitled to mark-room passes head to wind or leaves the zone.

(e) If there is reasonable doubt that a boat obtained or broke an overlap in time, it shall be presumed that she did not.

(f) If a boat obtained an inside overlap from clear astern or by tacking to windward of the other boat and, from the time the overlap began, the outside boat has been unable to give mark-room, she is not required to give it.

18.3 Passing Head to Wind in the Zone

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.

Copies of these rules articles along with animated diagrams can be found at www.rcyc.ca > sailing > racing > know your rules