I'm from Pensacola, Fl and do a lot of diving out of there. There are some pretty good wrecks scattered all around. And some natural limestone if you go way out. I've done some snorkeling on the jetties in Destin and its always nice! The world's largest artificial reef , The Oriskany, is in between Pensacola and Destin. Its an awesome dive.
These guys are an awesome dive shop in Pensacola. Check out their website for all the dive sites in the area.
http://mbtdivers.com/Local%20Dives.htm