Hi all,

well all depends how full your sail can be. If the sail is to full, it will not create more lift, but less, because it is partly stalling. And less lift on a downwind leg is slower, as I said, you can forget about drag on downwind legs. So yes keep your sail flat, but not as flat as on a upwind leg. As mentioned before, tell tales on the leach will help to find the right point.

Finally I would not compare the settings of a solid wing with a soft sail. For most airfoil sections without slots more than 5%..7% camber will not improve lift capability, on a soft sail this might be the up-wind setting (including the mast in the camber calculation).

A bit off-topic: The performance of a wing sail against a modern squarehead sail has still to be proven. Last true competition was the rig selection for Stars and Stripes as far as I know, and soft sails has improved a lot since then.

Cheers,

Klaus