This dive site is part of a vibrant double reef system located offshore of the main Alligator Reef in the Florida Keys. It is characterized by a wide sand channel separating the two reef lines. Divers can explore extensive isolated boulder corals and impressive large barrel sponges, navigating along the reef contours and across the sand channel. While not explicitly historical, its name ties into the nearby Alligator Reef Lighthouse, a historic landmark.
The marine life here is diverse, featuring numerous reef fish species typical of the Caribbean, vibrant hard and soft corals forming the reef structure, and various crustaceans and invertebrates inhabiting the sponges and crevices. The deeper edges are known for occasional sightings of larger pelagic species, including powerful bull sharks and majestic great hammerheads, adding an exciting element to the dive.
The best time to visit Alligator Deep for the clearest waters and highest chances of pelagic encounters is typically during the drier seasons, though the Florida Keys offer year-round diving. Divers should be prepared for potential currents, especially on the deeper side. Freedivers will find the varying depths from 10 to 20 meters (with some areas reaching 30m) ideal for exploration, while snorkelers can enjoy the shallower sections of the reef and the sand channel's ecosystem.
