Look up the Florida pilot websites, there are some tips and such on how to get over there. I would stay above 10k, for the 172 that the altitude that is needed to be able to glide to land (anything that wasn't water) at all times. Getting wet is not an option, the coasties aren't that good.
You know the regs, life preservers, if you know anybody, see if you can barrow a set of the inflatables, that way you can put them in a place where you will actually have time to get them out if you end of going in the drink.
Sorry about all this doomsday stuff, but its better safe than sorry, I don't want to hear about anyone on the 11 o clock news if I don't have to.
Have fun, it's a blast there.