You should consider the sharpness of the hull at the sheerline versus the bottom of the hull. I would not go less than a 1/4 inches radius at the sharpest part of the bow..normally around the sheerline, because of the difficulty in fiberglassing. However, as the hull angle flattens out on the bottom of the hull, you could have a 3/8 or 1/2 radius. I try to follow the natural lines of the kayak.

K.Greer