Might be your GB.... I've been using my GB Pro in the dry and in the damp sand with no problems. I have had to ground balance again when leaving the dry sand but have been able to use it without any problems in the damp. Also in the damp, I haven't had to turn down the gain any... I keep it around 85% in the damp and 100% in the dry.... now if I go over the truely wet sand, that is another story.... It is amazing how much small foil there is in the dry sand.
Cliff