yeah, it does go against the preemption statutes. FL 790.06 (12) covers the prohibited places and the beach is not anywhere on that list. I'd try the commissioners and if they don't want to give you a response, go to the DA. I never carry at the beach either, though. too tough to hide my gun and i don't trust that no one is going to go rootin thru my stuff while i'm in the water w/ my kid.
see the statute here: http://www.leg.state.fl.us/Statutes/...n%2006#0790.06