Dry Tortugas...a must see.
If snorkling and tourist-avoidance is something you seek....then head west to the Tortugas...and take ALL you want to drink with you. Did the fast-cat power-boat day-trip to Ft Jefferson this past summer and dove the surrounding beaches--EXCELLENT dive! Then did the local snorkle boat from Key West later...and was disappointed. You can get all kinds of info regarding the fort online. Would be a great destination if you have the time....and if you didn't have the time...do it anyway, (even if it is by day-trip ticket...the history is interesting.)