The development of the current sails is very simple because it is based only on two adjustments: downhaul and ashlar. Everything else, like the slats and the camber, is fixed in the sense that the adjustment is made once and then no longer touches. It remains only to determine the height of the boom which, like the clew tension, can be easily adjusted even in the water to find the best trim or even to adapt to the changing wind.
Windusrf Sail Downhaul tension
We must first of all identify the reference voltage, that is the “center” of our future regulations. This is also useful for adjusting the length of the extension. To get an idea, do the following: mount the tree and adjust the extension so that the total size corresponds as much as possible to the length indicated on the sail (luff). The reference voltage will be the one that brings the wall angle very close to the pulleys of the extension. Obviously we try to have a bit of judgment: if we don’t make it or if the tension is ridiculous it means that we will have to adjust the extension neglecting the luff parameter indicated on the sail. As the tension increases, the leech is loosened and at the same time almost horizontal folds are formed in the upper part. The reference voltage is the one immediately preceding the formation of the first folds.
Windsurf Sail: Tension of the clew
This is much easier: by mounting the boom with the length indicated by the sail manufacturer and bringing the clew angle almost to touch the terminal there is a usually precise reference.
Adaptation of the Windsurf Sail to different conditions
- overpowering: cocked downhaul beyond the reference voltage. Continue to fuck until the creases on the leech reach at least the second stick (on certain current sails there are signs like “min, med, max” to have a reference on how much to loosen the leech). Cleft tension higher than the reference one: displacement of the clew angle with respect to the zero of about 2 or 3cm. When the wind increases further, exaggerate with the downhaul but not with the clew otherwise you get the opposite effect because the sail loses the right profile. If you feel that you can’t manage to keep the sail closed anyway, move the trapeze florets back a few cm. With this type of tuning the sail tends to twist or open upwards (see second image)
- optimal wind: tensions should be the reference ones.
- weak wind (just enough) and / or gustate: low-fucked downhaul; no folds at the top: compared to the reference voltage, it loosens a little more. Low clew tension: spring the top to have a swollen sail until it touches the boom under gust. Be careful not to get into the condition in which the sail rests on the boom: the profile has become unstable and, worse, the sail is ruined. With this type of tuning the sail remains rather rigid at the top (see first image)