March 2016 - Proper Course - What Is It?

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March 2016 - Proper Course - What Is It?

In the last article, I talked about a situation where different boats have different proper courses and the conflicts that arise. I received several questions before and after that article which have led me discuss a different question – “What is a proper course?” The rule book definition is:
Proper Course
A course a boat would sail to finish as soon as possible in the absence of the other boats referred to in the rule using the term. A boat has no proper course before her starting signal.

Another way to put it is that your proper course is the course that you would sail if the other boat was not around. Sometimes the proper course is obvious. On an upwind leg, you would sail close-hauled or as close to the wind as possible without losing VMG. On a reaching leg, you would probably sail directly towards the mark. In other circumstances, it is not quite so obvious.

Last month, we saw the same diagram with two boats sailing a leeward leg. Blue, with a symmetrical spinnaker, is sailing directly downwind. In sufficient wind, this might be her proper course. If the wind were lighter, she might head up to keep her spinnaker full. Either of these could be her proper course, as long as the reason she was heading up was not related to another boat (for example if her spinnaker collapsed because a boat immediately to windward, where rule 17 applied was blanketing her, she could not head up and claim that as a proper course). Yellow is flying an asymmetrical spinnaker. They don’t sail well on a broad reach. Boats with asymmetrical spinnakers will almost always sail higher to increase their VMG to leeward, so Yellow’s proper course will be higher than Blue’s. You can see Green, also flying an asymmetric, sailing the same course as Yellow. The course that is being sailed by other boats with same sail configuration does not irrefutably prove that Yellow is on her proper course, but it can be a good indication of what the proper course might be.

If you are riding waves going downwind then it is quite likely that you will head up on one side of the wave and down on the other. It may not look like a steady course, but in this situation, it is the proper course.

In the next diagram, Blue and Yellow are sailing faster than three smaller boats in front of them. Rule 11 and rule 17 apply between Yellow and Blue. Rule 17 uses the term “proper course”. If Yellow were not there, then Blue would head up to go around these smaller boats, so she should now head up and do just that; she is not breaking rule 17 if she does.

A boat’s proper course may not be a hard-and-fast thing that is easily proven. ISAF Case 14 says, “Which of two different courses is the faster one to the next mark can not be determined in advance and is not necessarily proven by one boat or the other reaching the next mark ahead.” When a boat suddenly changes her course and claims that her new course is her proper course, she is likely to have much more trouble defending it, than she would if she had been sailing that course already. For instance, a boat may sail a higher course to get to a puff of wind that disappears when she gets there. Defending the new course may take some thought. In his book Understanding the Racing Rules of Sailing through 2016  Dave Perry says, “For protest committees, two reasonable criteria for judging a proper course are whether the boat sailing it has a logical reason for its being a proper course and whether she applies it with some consistency.”

Finally, I should say that there are no rules that say that a boat must sail her proper course. There are limitations that say that boats in certain circumstance may sail no higher than her proper course (rule 17) or no further from the mark than her proper course (rule 18.4). A boat can interfere with a boat on another leg as long as the boat doing the interfering is sailing her proper course. The definition of “Mark-Room” and the rules that use it entitle some boats to room to sail their proper course. Some sailors would like “proper course” to be a cut-and-dried prescription. I’d answer that it is mental challenges like this that help make our sport the pleasure it is.

© Copyright 2016 Andrew Alberti
Posted: 3/1/2016 1:14:29 PM by Andrew Alberti

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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
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 [email protected].


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