Beerman, with all the good posts you have sufficient suggestions for this trip.

For the next Key West vacation, might I suggest a half or full day trip to Fort Jefferson in the Dry Tortugas located 70 miles west of Key West. You may either take a ferry or fly aboard a vintage de Havilland Otter that has been updated with a modern 1000 shp turboprop engine and CRT avionics. A bit pricey but well worth the sightseeing experience. http://keywestseaplanecharters.com