by Jon Emmett
Before we even go on the water, we need to think about what sort of day it will be. Will it be a shifty day and we need to tack on every shift? Or will it be a persistent shift or strong current day and we need to get to one side of the race course? Or is pressure the most important thing and we need to spend the day looking for darker patches on the water? Well, in light winds this last point, pressure becomes more important because the difference in hull speed becomes very large with differences in wind speed, when the wind speed is low.
Forecasts: Remember it is the weather as it affects our Laser racing that we are interested in, so although there maybe a general trend in the day for the wind to go left or right, if this is very slow and our beats are only approximately 15 minutes long then it is far more important to sail in the wind you see, rather than preparing for what may happen with the wind.
Note that in light winds, there will likely be large pressure differences across the course. Often, but not always, you only get consistent wind across the whole course area when the average wind speed reaches around 8 knots (this will of course vary according to the topography).
Rig setting is about creating power in the rig without too much drag. This is a delicate balance and may require lots of adjustment if the wind strength is up and down, or a continual adjustment one way or another if the wind is gradually increasing or dying (maybe you have this information from the weather forecast). Upwind you need to use the kicker to match the luff curve to the mast bend, whilst downwind you need to let off a lot of kicker to prevent leech hooking.
Downwind, since you will most likely be unable to surf and definitely unable to plane, you need to think about creating a good flow over the sail and at the same time, sailing the minimum distance to the mark. This most often means the tack which is allowing you to sail most directly to the mark. In all but the very lightest of winds, sailing by the lee with windward heel and the boom very slightly forward of 90 degrees creates good low. When the wind drops below 5 knots (and maybe you can see your reflection in the water) it is time to move your weight forward and balance the boat to leeward to help the sail fill and sail a more reaching angle.
This top tip about leeward heel also applies to boat handling when at the end of a tack or gybe you may wish to exit with a small amount of leeward heel (which means ducking down to leeward after rolling the boat flat) to allow the sail to fill rather than flap.
Clean wind is especially important in light air because of the speed loss both up and downwind that dirty air creates. In light winds we often have flatter water and therefore it is easier to tack and gybe without losing ground up/down wind. So it is definitely worth tacking/gybing in order to keep clean wind.
Jon Emmett’s book on tactics, Be Your Own Tactics Coach is now available both as a paperback and as an e-book.