Thanks Rolf,

as I said, I don't how to use this numbers. But I have found a pictures of Gilos Blade Sail with open downhaul and it looks pretty much like my sail, at least in my eyes.
I agree with the excessive camber, but with the downhaul I can reduce it quite efficient. No pics in the moment, sorry.
I will continue with on the water testing, because I can understand what tell-tales tell to me.

Quote
I think your problem is not the leech but the sail shape in the lower part, i.e. chamber too much aft and too flat close to the boom


Claus,

I tried various outhaul tension (on the water) and I am pretty sure that neither the sail is to flat there nor is the camber to much aft. Both more camber and more forward position of camber let the bottom stall earlier.

Thanks again for your input.

Cheers,

Klaus