Once you round the windward mark, you must stick to your downwind strategic plan as closely as possible. Like your upwind strategy, this plan is dependent on a set of moves called tactics.
Tactics are the tools and techniques you use to implement your strategy amidst a fleet of boats. Without smart tactics, you will get blanketed from behind, luffed to the moon and pushed to the outside at marks. Your goal, then, is to control your own destiny and not let other boats push you around.
Runs
As we discussed in the previous chapter, runs are similar in many ways to beats. In fact, as multihull and iceboat sailors have discovered, runs offer some of the most exciting tactical sailing, largely because it's very easy to change jibes without losing distance. Here are some general principles to consider.
Ladder rungs: On a run, you can use the 'ladder rung' principle to determine relative position, just like on a beat. Use your tacking lines or a hand-bearing compass to identify your ladder rung and judge how you are doing relative to other boats. The important thing about ladder rungs is that they help you use other boats to identify gains and losses due to differences in wind angle or velocity.
Protect the inside: Perhaps the most basic tactical principle on runs is to protect the side of the course that will be inside at the next mark rounding. On a typical port-rounding course, this means you should favor the left side (looking downwind). By approaching the leeward mark from the left, you will not only be inside of the nearby boats, but you will also have the starboard-tack advantage. Like upwind crossing situations, you must anticipate what will happen when two boats converge on a run. The goal is to emerge from the crossing with your strategic and tactical goals still in place. If you want to be on the inside, for example, then you should head up behind a starboard tacker to position yourself to the left and get the right of way at the next crossing. The starboard tacker can defend against this, and protect her inside position, by jibing early.
Attacking: Runs are fun because they offer hope for the boats behind. Unlike beats, downwind legs allow a boat behind to use her wind shadow to slow a boat ahead. In most conditions, your "dirty air" will extend at least several boatlengths to leeward. Your object is to place this shadow right on top of the boat you're trying to catch. To do this, line yourself up with the apparent wind (not the true wind) of your opponent. Fortunately, most boats have wind pennants at the top of their masts that point directly to the place where an attacker should be. If your competitor's mainsail looks a little light, or his spinnaker curls a little funny, you'll know you are in the right place. Your windshadow can be a potent come-from-behind tactical weapon. Use it not only to slow a boat ahead, but to force that boat to jibe toward the unfavored side. Just be sure your wind shadow doesn't fall astern of the boat ahead -- this is the most common mistake made by would-be attackers.
Keep clear air: If you are the boat that's being attacked, be sure to keep your air clear. You must always know where your apparent wind is coming from. This is the area where you don't want other boats to be. Your spinnaker trimmer is often the first person who can feel the presence of bad air. If another boat gets close to your wind, you have two options for keeping your air clear: either head up or jibe. This choice must be based on your general strategic and tactical considerations. In Figure 6, for example, the boat that's ahead should reach up to clear her air so she can keep going toward the favored side. If the boats were close to the leeward mark, however, she might jibe for clear air and the inside position.
Reaches As we said in the last chapter, reaches are unique and therefore require a different set of tactics than beats or runs. Of all the course legs, reaches produce the fewest position changes. You might argue that this makes reaches tactically boring, but the opposite is probably true. Because of their subtleties, reaches require sophisticated tactical moves. The first reach, for example, is challenging because your tactical goals are conflicting. You must usually go high to protect your wind and, at the same time, go low to get to the inside at the jibe mark. The relative importance of these two goals depends on many factors, including the length of the leg and your proximity to the mark. Let's look at some of these in more detail.
The delayed set: There is no rule that says you have to set your spinnaker right after the mark. So before you pull up the halyard, look around. Are there a bunch of boats with wrapped spinnakers just ahead? If so, your best tactical move may be to delay your set and sail high for a bit. This works especially well if it's windy and/or the reach is a tight one.
The "passing lane": One good reason to go high right after the mark is to get up into the passing lane. This is like the left lane of a highway -- it's an area to windward of another boat (or boats) where you can sail by unobstructed. Boats in the passing lane get puffs sooner and have less disturbed water. The problem with trying to pass another boat close aboard is that, as soon as you start catching up, he will simply head up to keep you from going over him. If you're in the passing lane, however, he will either let you go by (because you won't hurt his air too much) or he won't realize you're going over him until it's too late to get up to you.
Defending: As we just mentioned, the best defense against a boat threatening from behind is to head up in front of him. The basic idea is to stay between your competitor and the next mark. Just make sure that you keep your air clear ahead of him. Your goal is to defend successfully and, at the same time, stay as low as possible so you don't lose to the rest of the fleet. If your competitor blindly goes high, try using moral suasion to discourage him, or at least to explain the risks of his actions.
Luffing: If another boat is threatening to pass you to windward, your final tactical weapon is a luff. To be effective, a luff must be carried out sharply, if possible by surprise. It should be initiated after the other boat becomes overlapped to windward and before they take your wind (your goal is to be able to luff them hard before they get mast abeam). Keep in mind that luffing is a last resort. It may be the best way to stay ahead of one boat, but it can be very costly with respect to the rest of the fleet. If possible, it's better to prevent the need to luff. You can do this in two ways: 1) if the other boat is faster, let him go by; or 2) try a deterrent such as "I will luff you to the moon if you try to pass me to windward."
Reaching high: It's a good idea to sail toward the next mark whenever possible, but there are times when your tactics should be to stay high or low. It's good to go high, in general, when there are many boats close behind. Going low in this situation would be too risky; if one boat rolled over the top of you and took your wind, you might see a train of boats going by. Staying high is especially good on the second reach, where the windward boat will be inside at the leeward mark, and on tight reaches.
Reaching low: On the other hand, going low is a good idea when you have a large pack of boats just ahead. This pack will tend to fight each other and go high; the best way to gain distance is by sticking to the rhumbline as closely as possible. The low road is especially attractive on the first reach, where the leeward boat will be inside at the jibe mark. It also works much better on broad reaches than on tight reaches (where there is a lot of bad air to leeward).
Extending your lead: Sometimes the best thing you can do is forget the boat(s) right next to you and concentrate on gaining distance on the fleet. This is especially true early in a race, and it requires a lot of patience. One example is two boats on a reach that are leading a larger pack. The second-place boat could reach up higher and try to pass to windward of the first-place boat. But the chances are this will only end up in a luffing match that costs both boats distance on the fleet. The best thing #2 can do is hold back and follow #1 until they are farther ahead of the pack; then he can attack.
Drafting: Anytime a bigger boat goes buy on a reach, you can catch a free ride by drafting. To do this, you have to fall in right behind the bigger boat as it goes by (preferably to leeward). Your best chance of getting a tow is to stay very close behind the bigger boat -- on her first stern or quarter wave if possible.
Avoid laylines: As we discussed in the last chapter, getting to the layline early will cost you distance on the fleet if the wind shifts. Another reason to avoid laylines is dirty air. As soon as you set yourself up on the layline, you're just asking for another boat (or boats) to come sit on you with their bad air. So try to stay off the layline until you get fairly close to the mark.
When you get to the end of the run, there are several ways to approach the leeward mark. As we've just seen, a boat that approaches on starboard tack risks losing to other boats if the wind shifts or if he gets bad air. The advantage of this approach is that you have plenty of time to prepare for your spinnaker takedown.
Approaching on the other layline brings with it the same risks of losing on a wind shift or dirty air. It also requires good crew work because you will have to do some sort of jibe-takedown-rounding at the mark. However, the big advantage of this approach is inside position at the mark.
In many situations, a compromise may be best. In this approach, avoid the laylines until the very end, so you can take advantage of wind shifts and/or maneuver to keep clear air. You also want to come into the mark on starboard tack, so you keep the right of way and inside position on most other boats. Position yourself you you jibe onto the starboard layline just far enough from the mark so you have time to complete a good jibe and then