That's a lot of open water from Sarasota to Key West. lots can happen there, not the least of which is you would get run over by mysterious, high-speed craft with a funny hemp-like smell running with no lights on after dark.

And it's an exercise area for the base down there, so you actually face the possibility of being hit by ordinance "residue" (flares, etc)

Oh, and the abandoned oil rigs that aren't marked..