You certainly wouldn't want to be using F18 boards in the F16's, perhaps we should be thinking along the lines of longer length higher aspect ratios to get the drag down even further. If you are already lifting the baords on the Viper then that may be a good route to go.

Certainly on my A which was set up for a lighter weight guy at about 75kgs with very small High Aspect boards, I can over power those boards quite easily with my lardy 95kgs, so there is a balance there to be looked at and experimented with. Certainly most boats are set up for duals so for us Uni's there might be quite a bit of gain to be had.