These boards are primarily made for displacement.  Deep vee, near plumb bows and pin tails all help reduce residual drag (wave drag).  The bottoms are flat to slightly rounded, with "tea cup" profile rails to reduce wetted surface and skin friction drag.  The displacement is matched to within 5 lbs. of the user's weight.  This also helps minimize  the amount of wetted surface.  Stability is enhanced with the lowered footwells, which are ideally placed just above the waters surface.  With the design software, it is possible to predict exactly how low to put the footwell to match the users weight, and thereby maximize stability.