You're racing a keelboat, say a J/24, in 10 knots of breeze. You're halfway up the first beat, on port tack, and crossing most of the 40-boat fleet.
"We're on a big lift," says the tactician, staring at the compass.
"And it looks like there's more wind ahead," you add, looking past the telltales on the jib.
Your tactician, who is also the genoa trimmer, slides to leeward to trim the sheet a little. All of a sudden the expression on his face turns from glee to panic. "Tack!" he screams. "Tack now!"
As you throw the helm over and the boat pivots sharply, you see the starboard tacker only a few feet away. You have succeeded in avoiding a foul, but your tack is terrible, and the other boat rolls you almost immediately. Besides having bad air you are now on the headed tack, sailing away from the best breeze.
Does this scenario sound familiar? If it does, you know the biggest mistake here was lack of anticipation. The sailors here didn't see the starboard tacker until the last second, and the only way they could avoid a collision was to crash-tack. Unfortunately, this put them completely out of sync with their game plan, which had been working so well.
Anticipation is especially important whenever two boats converge on a beat. The reason is that you need time to consider several factors: First, what is your strategic plan? Do you want to keep going in the same direction, or tack and head the other way? Second, what is the relative position of the two boats as they converge? Is your bow far enough in front that you can make a lee-bow tack? Third, are there tactical considerations regarding the other boat?
Let's look at a number of converging situations and figure out whether you want to cross, tack, or duck. I've indicated which side of the course you think is favored and how close you are to crossing the other boat.
1
Your tack: Port
Favored side: Left
Boat positions: You are not quite crossing S.
This is the perfect time to execute a lee-bow tack. Your goal is to time your tack so you end up as close as possible in front and to leeward of the other boat (of course, be careful about tacking too close). The advantage of this move is two-fold: It gets you headed toward the favored side and forces your competitor to tack the other way.
2
Your tack: Port
Favored side: Left
Boat positions: Approximately bow to bow
This situation is the same as #1, except you aren't close enough to tack into a lee-bow position. In this case, head for the favored side by tacking well before you reach S. Leave enough room between yourself and S to maintain the option to tack back onto port; the last thing you want is to get pinned (or, worse yet, rolled) by tacking too close underneath the other boat.
3
Your tack: Port
Favored side: Right
Boat positions: Approximately bow to bow.
This is the classic time for a well-executed duck so you can keep going toward the favored side. Your goal is to be closehauled as you pass the leeward corner of the other boat's transom, so bear off early and head back up on the wind as you get closer.
4
Your tack: Port
Favored side: Right
Boat positions: You're not quite crossing S.
This situation is very similar to #3, except you're closer to crossing ahead of S. If you want to save yourself a big duck, try a slightly risky move. When you're several boatlengths from the other boat, ask them (in a very loud voice) whether they'd like you to cross ahead or tack (some people say "Cross or slam?"). You're gambling that S would rather duck slightly behind you than have you tack right in front of them. Try to get an answer from S before you lose the option to duck behind if they say "Starboard."
5
Your tack: Starboard
Favored side: Left
Boat positions: P may be able to lee-bow you.
This is definitely one of the toughest crossing situations. If P is almost able to cross you, there may be no way to prevent a lee-bow tack. However, if P is not quite that far ahead, try this move: When you're several boatlengths away, crack your sheets slightly and head off a little toward the other boat. This helps you build speed and forces P to tack sooner. As soon as P begins to tack, head up sharply to gain distance to windward. Even if you eventually get squeezed off, this move will often buy you more time on starboard tack
.6
Your tack: Starboard
Favored side: Left
Boat positions: P is not quite crossing you.
Don't let people on your boat blindly call out "Starboard" to every boat you approach. When you want to keep going left, it will be to your advantage to let a port tacker cross ahead, even if this means you must bear off behind him. Just make sure you communicate your intentions loudly and clearly by waving the other boat across and yelling something like "Go ahead!" An added advantage of this move is that P will consider you a good guy.
If it looks like the other boat is determined to tack in front of you, bear off slightly toward her when you're still three or four boatlengths away. This forces the other boat to tack sooner. It also gives you better speed to head up as soon as she begins to tack. Your goal is to establish enough of a windward berth so you can keep going left with clear air.
7
Your tack: Starboard
Favored side: Right
Boat positions: P is ducking you.
In moderate air and smooth water, you might consider a "slam dunk." As soon as P's bow reaches the leeward corner of your transom, go into a tack. If done right, you'll end up to windward of the other boat, pinning him on port tack. This works best when you're near a starboard-tack layline and you need to control the other boat for a short distance. Don't try this in light air or or chop, however, because the other boat will be able to squeeze you off.
8
Your tack: Starboard
Favored side: Right
Boat positions: P is not quite crossing you.
When you don't want to use a slam dunk, there are several other ways to protect the right side. The first is simply to continue on starboard tack, force P to tack, and then tack yourself (A). The advantage of this is that you end up going the right way while your competition heads the wrong way. The danger is that P will simply duck you at the last second.
Even if P does begin to duck, you can usually tack right in front of her (B). This is a very effective move because you end up in a lee-bow position. It's also risky because you take the chance of breaking rule 13 ("Tacking too Close"). As long as your tack doesn't force P to make a further alteration of course, however, you're OK.
A third, more conservative option, is the inverse of #2. As soon as you see a converging situation, tack onto port and head toward the favored side (C). Position yourself far enough from the port tacker to keep the option to tack back onto starboard without tacking too close.
Good anticipation, especially in crossing situations, can help you stick to your game plan. You may even start believing that crossing situations are opportunities for gain rather than chances to lose.