In the first diagram, Red and Green look exactly the same as in the second diagram last month – Red has established an overlap to leeward of Green from clear astern. At the other end of the line, something very similar has happened – Yellow has established an overlap to leeward of Grey from clear astern. Yellow and Red are restricted by rule 17 from sailing above their proper course. We saw last month that the definition of proper course says that boats have no proper course before their start signal, so essentially rule 17 has no effect until position 4, when the start signal goes. Last month, I said that Red had to go down to a close-hauled course. The definition of proper course does not say anything about a close-hauled course. The definition says, “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.” This is the course that Red or Yellow would sail in the absence of Green or Grey. If Green was not there, there is no reason for Red to luff above close-hauled since that would make her sails luff and she would slow down. Red’s proper course, is to sail to the next mark as quickly as possible, which means that she would sail close-hauled.
At the other end of the line, things are little different. Yellow is slightly below the pin. If Grey was not there, Yellow would pinch up to shoot the mark, being careful not to hit it. This is therefore Yellow’s proper course. Yellow cannot sail above her proper course, but since her proper course includes shooting the mark, she can luff up to do that. Since Yellow is the leeward boat, rule 11 requires Grey, as windward boat, to keep clear so Grey has to luff up as well. As soon as they are past the mark, Yellow’s proper course is to sail close-hauled, so she must do that. The rule for both boats is the same – they cannot sail above their proper course, but applies differently since the proper courses are different. Yellow must be careful when she is shooting the mark, not to go past head to wind. If she does go past head to wind, she will no longer be the leeward boat, she will be a tacking boat, and rule 13 will require her to keep clear of Grey.
Yellow and Red both must be careful to give Grey and Green room to keep clear when they luff. Although Yellow and Red are the right-of-way boats, the rule is not absolute; in this situation, when right-of-way boats alter course, rule 16 requires them to give room to keep clear. They can’t luff too suddenly or too quickly.
In the second diagram, we see a different type of luffing before the start. Green and Red are heading up into the wind to check the starting line. Both boats are head to wind at position 4, both checking the line. The difference between the two boats is that Green started on starboard and Red started on port. Neither boat has crossed head to wind so according to the definition of tack, which in turn relies on the definition of leeward and windward, they both remain on the tack they were on before they luffed into their wind-check. Accordingly, Green is still on starboard and Red is still on port. Yellow must keep clear of Green since Yellow is on port tack. Yellow also has to keep clear of Red, since Yellow is to windward of Red. If another boat came in from the other side on starboard tack, in a mirror image of Yellow, then Red would have to keep clear of her. It is always good to do your wind-check starting from starboard tack. It is important though, not to cross head to wind. If you cross head to wind, you are tacking, rule 13 kicks in and you lose right of way.
Leeward and Windward A boat’s leeward side is the side that is or, when she is head to wind, was away from the wind. However, when sailing by the lee or directly downwind, her leeward side is the side on which her mainsail lies. The other side is her windward side. When two boats on the same tack overlap, the one on the leeward side of the other is the leeward boat. The other is the windward boat.
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.
Tack, Starboard or Port A boat is on the tack, starboard or port, corresponding to her windward side.
13 WHILE TACKING
After a boat passes head to wind, she shall keep clear of other boats until she is on a close-hauled course. During that time rules 10, 11 and 12 do not apply. If two boats are subject to this rule at the same time, the one on the other’s port side or the one astern shall keep clear.
16 CHANGING COURSE
16.1 When a right-of-way boat changes course, she shall give the other boat room to keep clear.
17 ON THE SAME TACK; PROPER COURSE
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.