Remember that on a stock high performance windsurfer (if you know what you are doing) you have the capability of going in the 40 MPH range…and the foot straps work just fine when you have them adjusted right…If a windsurfer can crank 35-40 mph on a reach in 30 mph+ wind and 2’-3’ chop…stuff the nose…get thrown over the handle bars…skip 3+ times before coming to rest…and have absolutely no leg/ankle problem….If that’s the case, (and I can tell you it is from personal experience) I say you shouldn’t have any problem on the typical catamaran. It is when you try to get too much of your foot forced in the strap, that is when you break things. Get a good quality adjustable windsurf strap and you can tweak them just perfect…and they will stay at that setting. Go cheap and you will be constantly adjusting them as they loosen up.

Regards,
Bob