Speed & Smarts: Gaining ground to leeward

Tactics for protecting your lead and clear air on the run, by David Dellenbaugh.

One thing I hate on a reach or run is when the boat behind me sails higher than I want to sail. This forces me to sail above my VMG course in order to keep my air clear in front of them. I constantly worry about falling into their bad air and about losing ground to the rest of the fleet. These two pages describe a technique for sailing as low as you can and still keeping your air clear. Before you resort to this approach, try two things. First, as soon as the other boat starts heading high, luff up sharply in their path to let them know there is no way you will allow them to sail over you. The windward boat is very enticed by the idea that they may be able to roll over you, so squash that early.

The second thing to try is talking to the other boat. Suggest they sail lower so that both of you can gain on the rest of the fleet. If neither technique works and the other boat keeps sailing high, you just have to make the best of this situation. Gybing is one way to keep your air clear and regain the ability to sail your VMG angle, but often this is not a strategic option. So what else can you do?

This situation is very common in match racing because the boat that's behind often sails high to take the wind of the boat ahead. The absolute key for the lead boat is to keep her wind clear in front of the other boat's wind shadow. In other words, she must make sure that her apparent wind (the wind she feels while sailing) is ahead of the other boat's spinnaker.

The diagram below shows one way to visualise this situation. It's fine to have a boat in your “green zone”, but you should start to worry if they get into the yellow. Allowing another boat into the red zone is an absolute no-no because they will take your wind. Of course, it's easy to keep your wind ahead of another boat; all you have to do is sail higher to increase your speed and bring your apparent wind forward. But this is not what you want to do – the goal is to sail lower (down to your optimal VMG if possible) and still keep your wind clear in front.

gaing_ground_leeward_2

One technique for doing this is explained further down. The basic idea is to keep your wind (just) safely in front of the other boat, and at the same time try to work further to leeward and away from them. In other words, pick a safe bearing to that boat and then try to hold this bearing constant while increasing your range (or distance) from them.

 

gaing_ground_leeward_3

 

Smart Moves for asymmetricals

WHEN you are sailing a boat that has a symmetrical spinnaker, the biggest gains and losses usually occur on the upwind legs. But with asymmetricals it's exactly the opposite. Gains and losses on the beats are relatively small – but on runs they can be huge! There are two main reasons for this. First, boats with asymmetrical chutes sail much higher angles downwind, which means they normally split very far apart on runs. With this much separation, even the smallest shifts or puffs can make a big difference.

The second reason is that asymmetrical boats tend to have a much wider range of performance. It's not uncommon for one boat to sail a knot or two faster, or 10 degrees higher or lower, than another
boat. This produces large disparities in downwind performance.
Because of the potential for big gains and losses, it is important to sail fast and smart on runs. Here are a bunch of ideas about how to do this, starting with two important points:

Gybe back through puffs
Symmetrical boats sail low angles that allow them to head in almost the same direction that a puff is going and therefore stay in that puff longer. Because asymmetrical boats sail higher angles, they tend to go across and out of puffs. To stay in better pressure longer, gybe when you get to the far side of the puff so you can sail back through it.

Play most shifts as persistent
On runs, asymmetrical boats sail fast with the wind so they don't experience as many shifts. In fact, even if the wind direction is oscillating. they might see only one shift during the course of a tenminute run. Therefore, they should play that as a persistent shift.

pic1

 

This article is extracted from Speed & Smarts, a newsletter
published by David Dellenbaugh filled with how-to information for
racing sailors. Dellenbaugh, tactician aboard the 1992 America's Cup
winner and an adviser to the German United Internet team for the 2007
AC, besides being a top sailor is a skilled communicator on tactics,
rules and boathandling.

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