I've tried hydrating the night before or in the wee hours before I head out, but always they turn to rocks within the first hour and I just deal with it, until the thighs start cramping also. Does anyone else have that problem. I'm thinking its my fins because the way I swim im only giving short bursts. When the break is closer to the beach and I can stand I never cramp up. Any insight would be appreciated because its a drag to have to get out of the water to stretch while the sets are pouring in.