wh
(no login) | Re: LongerNo score for this post | December 10 2003, 9:22 AM |
A couple thoughts on this..
The current dimensions are fairly well suited to using windsurfing sails for the following reasons:
1. The rear beam width (9 foot with the foils on ice)has been tweeked for the windsurfing sail center of effort height. For a given ce height, if you make the rear beam shorter, the boat tends to hike more. Make the beam wider and the boat tends to slide more. Balanced is somewhere in between. Since windsurfing sails have been designed around humans, they have about the same height CE regardless of the sail size and the boat behaves very similar regardless of sail size (the upright sail also helps here because the CE also doesnt move forward much when a smaller size is used).
2. Because of the pre-stressed mast, the mast bends forward to the mid section and than rakes back at the top. This allows the sail ce to be put forward to balance with the boats center of gravity but still allows the pilot to sit comfortably "under" the sail. If the top of the sail raked back even further, it would probably lower drag a little but its not bad as is.
3. Also because the sail is pre-stressed with the downhaul rigged before the sail is put on the boat, it "can" have a good shape in very light winds and also puts less stress on the boat.
Im rambling now... but I think the point could be that if you make the rear beam wider, there is a good chance that you will want a sail with a higher CE. Of course, that is simply a higher aspect sail which will be more efficient and faster than the smaller boat using a windsurfing sail but now you also have to design a sail. Ive never tried it before (been reasonably happy with windsurfing sails but I also modify them) and have a lot of respect for how difficult it is to get things right. But it probably would be a well behaved and fast boat..
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