I remember seeing a youtube vid on this site a while back - it was a camera mounted on a formula board looking down at the fin - the fin was flexing big time to leeward.

so... just wondering what effect that could have on efficiency and performance - ie as the fin flexes away does it lose performance (drag increase, increased chance of cavitation)?

For a pure speed unidirectional run (ie sandy pt..) then could it be beneficial to have a fin that was curved to windward and as it is loaded up it straightens out?