Excerpted from Understanding the Racing Rules of Sailing
by Dave Perry
Illustrations by Brad Dellenbaugh

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.

This is the most subjective definition in the book. It is also very important, particularly in applying rule 17 (On the Same Tack; Proper Course). The concept is very straightforward: your proper course is the course you think will get you from the starting line to the finishing line as quickly as possible, taking into account all the factors that will affect your speed. Typically, different sailors will have different ideas on what their fastest course is; thus different boats will have justifiably different proper courses.

One way to visualize this concept is to imagine a Time Trial. You and nine other sailors show up to race around a fixed-length triangle course, one at a time; the one with the fastest time wins. Around the windward-reach-reach course there are wind shifts, grandstands and a small man-made island on the second reach for the press and photographers. You start. You’ve already calculated the fastest path up the first beat, accounting for wind shifts, waves, current, time lost while tacking and so on. Down the first reach, as you approach the grandstand area you notice it’s creating a huge wind shadow so you bear away to avoid the light air and break through to leeward as quickly as possible. On the second reach, you’ve calculated that passing to leeward of the press island is the shortest, fastest route to the leeward mark. You finish.

The next boat starts. But this boat goes a different way up the beat. And it doesn’t think the grandstand’s wind shadow is that bad, so it doesn’t bear off as much. And finally it passes the press island to windward and finishes. Both boats were trying to race and finish as quickly as possible and so they were both sailing proper courses. In fact, all the boats may have had different opinions as to the fastest course that day. The course each boat sailed was a proper course.

L has become overlapped from clear astern and then luffed above her proper course solely to make it more difficult for W to stay ahead of her. In W's absence L would not have luffed at all. Therefore, L has broken rule 17.1 by sailing above her proper course.

Clearly it is possible that there may be several proper courses at any given moment, depending upon the particular circumstances involved. However, because it is often difficult to prove when someone is actually on a proper course as opposed to sailing extra high or low for tactical purposes, ISAF Case 14 suggests, “Which of two different courses is the faster one to the next mark cannot be determined in advance and is not necessarily proven by one boat or the other reaching the next mark ahead.” 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.

The phrase “in the absence of the other boats referred to in the rule using the term” clarifies which boats to “remove” when determining whether a course is a proper course or not. Note that it certainly does not mean ‘in the absence of all the boats in the race.’ Let’s say you and another boat are sailing down a reach. You catch up and become overlapped to leeward of the other boat (W). Rule 17.1 (On the Same Tack; Proper Course) tells you that you cannot sail above your proper course while overlapped with W. Because W is the “other boat” referred to in rule 17.1, your proper course is your fastest course in the absence of W.

L is "limited" to sailing no higher than her proper course because she became overlapped from clear astern. However, L decides that she will arrive at the gybe mark sooner by luffing and sailing to windward of the pack in front of her. Because she would do this even in the absence of W, it is a legitimate new proper course for L and W must keep clear under rule 11.

As you and W continue down the reach, you begin catching up to a group of boats in front of you going slowly. Now you have to decide whether to head up and try to pass the group to windward, or bear away and try to pass them to leeward. You decide that you will arrive at the gybe mark faster by heading up and passing the group to windward, but by heading up, you will collide with the windward boat. In this case, heading up can be considered your proper course because you would do so even in the absence of W.

The point is: your proper course should be based on what will get you to the next mark and ultimately to the finishing line as quickly as possible, not on a tactical consideration such as heading up to cut off a nearby windward boat. Note that the rules referring to proper courses are rules 17.1, 17.2, 18.1(b) and 18.4; and C2.2 and C.10 (match racing) and D1.1(a) (team racing).

Notice also that there is no proper course before the starting signal. That is because a proper course is the course sailed to finish as soon as possible. Obviously, you can’t start racing toward the finishing line until you are allowed to start; therefore, there is no proper course until after the starting signal is made.

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