July 2012 - Luffing Rights

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July 2012 - Luffing Rights

One area of the rules that seems to continue to cause questions is the area of luffing rights – who can luff? – and who can’t. This month I will start with a review of who has luffing rights. Next month I will cover what you can do if you don’t have them. I need to start by explaining that luffing rights is an informal expression that is not in the rule book. Some judges would prefer that we not use the term, but I find it useful. The concept appears in the negative in rule 17.
If a boat clear astern becomes overlapped within two of her hull lengths to leeward of a boat on the same tack, she shall not sail above her proper course while they remain on the same tack and overlapped within that distance, unless in doing so she promptly sails astern of the other boat. This rule does not apply if the overlap begins while the windward boat is required by rule 13 to keep clear.

Clear Astern and Clear Ahead; Overlap   
One boat is clear astern of another when her hull and equipment in normal position are behind a line abeam from the aftermost point of the other boat’s hull and equipment in normal position. The other boat is clear ahead. They overlap when neither is clear astern.However, they also overlap when a boat between them overlaps both.

These terms always apply to boats on the same tack. They do not apply to boats on opposite tacks unless rule 18 applies or both boats are sailing more than ninety degrees from the true wind.

Rule 17 describes the one situation where a leeward boat does not have luffing rights. Almost all other leeward boats do.

(click on the diagram to see a larger cleaner version)

In the diagram the Blue boat in position 1 is clear ahead of Grey and Yellow. Both Grey and Yellow are sailing faster and establish overlaps from clear astern at position 2. Yellow establishes the overlap to leeward. She is within two of her hull lengths of Blue. If we look at the wording of rule 17 we see that these two conditions – establishing the overlap to leeward and being within two of her hull lengths – mean that rule 17 applies to Yellow. Therefore, she is not allowed to sail above her proper course while Blue and Yellow remain overlapped on the same tack within two hull lengths of each other. This restriction continues until position 7 when she is clear ahead. Since there is no longer an overlap.at position 7, Yellow is now allowed to go above her proper course. Although the term isn’t used in the rules, saying that Yellow has “no luffing rights” is a handy way of describing her situation from position 2 through position 6.

Grey establishes the overlap to windward of Blue. Since her overlap is established to windward of Blue, Grey is not subject to rule 17.  Blue is now overlapped to leeward, but she did not establish the overlap from clear astern, so she is not subject to rule 17. Blue can head up and make it more difficult from Grey to pass (though whether this will benefit Blue depends on several other factors). From position 2 through position 6, we say that Blue does have luffing rights.

There are several ways of establishing an overlap that are not limited by rule 17.

In the second diagram Red tacks from port to starboard. At position 1, Red and Green are not overlapped. At position 3, they are on the same tack and overlapped. This overlap was not established from clear astern so rule 17 does not apply and red has luffing rights. 

Green and Brown are not overlapped at position 1. Green is sailing quicker and higher and establishes an overlap from clear astern at position 2. The boats are still more than two hull lengths away when the overlap is established so rule 17 does not apply.

(click on the diagram to see a larger cleaner version)

Purple and Orange are sailing on opposite tacks. Although the definition of an overlap states that one cannot “apply to boats on opposite tacks”, these boats are overlapped because “both boats are sailing more than ninety degrees from the true wind.” No matter how the overlap was originally established, the limitations of rule 17 cannot apply since they have not remained on the same tack since the overlap was established. At position 2, Orange gybes and they are now on the same tack so the windward leeward rule (rule 11) does apply but since they have not  “remained on the same tack and overlapped” on the same tack since the overlap was established rule 17 still doesn’t apply, so Orange has luffing rights.
Next month, we will talk about what these boats can do with their luffing rights.  
© Copyright 2012 Andrew Alberti
Posted: 7/1/2012 1:08:16 PM by Andrew Alberti

Trackback URL: https://rcyc.ca/trackback/6b5228e1-dfa9-42ed-90bd-95cbb6044568/July_2012_-_Luffing_Rights.aspx?culture=en-US

This page provides links to a set of articles original published in Kwasind magazine. The versions here include animated diagrams. The original articles can be found within the original magazines which are available online back to January 2007. 

Articles before December 2020 are based on the Racing Rules of Sailing 2009-12 or 2013-2016 or 2017-2020 and have not been updated to reflect the changes that apply as of January 2021 with the publication of the Racing Rules of Sailing 2021-24. A copy of the new rules can be found on sailing.org.
Andrew Alberti has been writing these monthly articles in the Kwasind since early 1997.  They explain the Racing Rules of Sailing. Andrew is an International Judge and National Umpire. He is a member of the Sail Canada Rules and Appeals Committees. The interpretation of the rules contained in the articles is Andrew's and not that of the RCYC or any of the committees he sits on. 

Send your questions to Andrew at kyrules@alberti.ca.


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