Getting around the windward mark

Rules on sailboat racing require sailors to give way to boats that are within the two-length-zone of the windward mark. A boat is deemed about to pass the windward mark when its speed increases and goes through wilder winds and waves. The boat needs more control at this point.

In the last two issues, we’ve followed a fleet of boats from their start on up the first windward leg, applying the racing rules to common boat-to-boat situations. This month we’ll look at snapshots of that same fleet of boats as they round the windward mark, discussing the rules situations that crop up there. In each case I’ll assume the mark is to be passed to port.

In the first scenario, Paul and Mary have overstood the weather mark and are screaming in on a close reach overlapped on port tack. Until they are “about to pass” the mark, Paul, as windward boat, is required by Rule 11 to keep clear of Mary. When they are close enough to the mark that they are “about to pass” it, then Rule 18.2(a) begins to apply and Mary must give Paul “room to pass the mark.” ISAF Case 84 discusses the meaning of the phrase “about to pass.” When a boat becomes “about to pass” a mark depends on several factors; the faster she is approaching the mark, the wilder the wind and waves, and the more sailhandling she has to do to round the mark, the sooner she becomes “about to pass” it. When she reaches the two-length zone, she is almost always “about to pass” the mark.

When they are “about to pass” the mark, Mary is required to give Paul room, including the room he needs to begin his tack around the mark. However, the moment Paul turns past head-to-wind, he becomes a starboard-tack boat while Mary is still on port tack. At that moment, Rule 18.2(a) ceases to apply because the boats are then on opposite tacks on a beat (see Rule 18.1(b)), and Paul is required by Rule 13 to keep clear of Mary. That will not be burdensome because his course and momentum will be carrying him away from her. After they both have tacked onto starboard tack, a new overlap begins between them. As they bear off onto the course to the next mark, Paul will have right-of-way under Rule 11 and also the right to sail above his proper course because the new overlap began with the boats side by side (see Rule 17.1).

Thelma and Louise are approaching the mark overlapped on starboard tack. Well before they entered the two-length zone, Louise crossed ahead of Thelma and tacked rather clumsily into a slightly overstood position. As a result of Louise’s slow tack, Thelma was able to overlap Louise to leeward. For this reason, Thelma, even though she has right-of-way as the leeward boat, is constrained by Rule 17.1 not to sail above her proper course. There’s a bit of foul current running, and Louise has reached down close to Thelma in an effort to blanket her and thereby prevent her from fetching the mark. Since Thelma is just below the layline, her proper course is to luff above closehauled and “shoot” the mark. By reaching off close to Thelma, Louise has put herself in a risky, position. If she sags down so close to Thelma that Thelma cannot shoot the mark without making contact with Louise, then Louise will have failed to keep clear and therefore broken Rule 11.

Ed and Fred are both approaching on port tack with Fred clear ahead. While the boats are on the same tack, Ed must keep clear of Fred (see Rules 12 and 18.2(b)). However, from his position, Fred cannot tack without placing himself in Ed’s path while turning from head-to-wind to closehauled on starboard. The moment Fred turns past head-to-wind, Rule 13 replaces Rule 18.2(b). Under Rule 13, Fred would have to keep clear of Ed until he was on a closehauled starboard-tack course. This gives Ed the advantage. He needs only to hold his course until he can fetch the mark, at which point he should be able to tack around ahead of Fred.

Pat and Stan are approaching on opposite tacks with Pat on port barely able to cross Stan on starboard. While they are on opposite tacks, Pat is required by Rule 10 to keep clear of Stan. Rule 18 does not apply (see Rule 18.1(b)), so Pat is not entitled to room from Stan to pass the mark. New Rule 18.3 begins to apply right after Pat tacks within the two-length zone. That rule makes Pat’s position very risky. If Pat tacks to leeward or just ahead of Stan, then he must keep clear not only while on port tack (required by Rule 10) and while turning from head-to-wind to closehauled on starboard tack (required by Rule 13), but also must not tack so close to Stan that Stan is forced to luff above closehauled to avoid him. If Pat tacks this close, he will break Rule 18.3(a). Furthermore, if Pat crosses Stan’s path and then tacks, he must do so far enough to windward that he is able to keep clear of Stan should Stan become overlapped inside him (see Rule 18.3(b)). Rule 18.3 is tough. To avoid breaking it when making a port-tack approach to a windward mark, you should make your approach at least three hull lengths to leeward of the mark so that you can complete your tack onto starboard before you enter the two-length zone. If you find yourself in the zone on port, you’ll be safe if you duck the transom of any nearby starboard-tack boats.

Ted and Alice are also approaching the mark on opposite tacks. Alice has overstood and is reaching down to the mark. Ted tacks from port to starboard inside the two-length zone. He completes his tack and assumes a starboard-tack, closehauled course without breaking Rule 13, but just after he tacks, Alice is compelled to luff to avoid hitting him. She protests.

Should Ted do a 720? No. Neither boat has broken a rule. As soon as Ted is on a closehauled starboard-tack course, he obtains right-of-way under Rule 11. At that moment, he must give Alice room to keep clear (see Rule 15). That Alice was able to luff and avoid contact indicates that Ted did not break Rule 15. Alice was forced to luff to avoid Ted, but she did not have to luff above closehauled to avoid contact. So Ted did not break Rule 18.3(a).

Tom, Dick, and Harry’s situation was described to me in an e-mail from a reader. Tom was hit with a sharp puff and capsized just as he was about to round the mark on starboard tack. Before Tom capsized, Dick thought he would easily cross Harry and tack around the mark ahead of him. Suddenly Harry and Dick are faced with a new situation. If Dick bears away to avoid Tom, he will not be able to cross Harry. Although Harry was on the layline to the mark, now he cannot make it past Tom without tacking.

Both Dick and Harry are required by Rule 21 to avoid Tom if it’s possible for them to do so. While Dick and Harry are on opposite tacks, Rule 18 does not give either of them any rights to room to pass the mark or the obstruction (Harry). It seems to me that the safest thing for Harry to do is to tack onto port, then back onto starboard right away, well before he is close to Dick. After Harry tacks onto port, there is a chance that Dick can put himself in a position to block Harry’s tack back onto starboard in order to beat Harry around both Tom and the mark. A riskier move for Harry is to hold his course on starboard and then tack when he is about to collide with Tom. This may force Dick to take Harry’s stern, at which point Harry can tack and block Dick from tacking onto starboard. If Harry can pull this off, he has a chance of rounding Tom and the mark ahead of Dick.

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