Alligator Reef

Alligator Reef is a shallow coral reef site marked by a historic 136-foot black-and-white lighthouse and a vibrant spur-and-groove reef that developed around the remains of the USS Alligator. Much of the reef lies in very shallow water, making it popular and accessible for snorkelers and divers, with abundant tropical fish and invertebrates sheltering among corals, crevices, and ledges. Dives are conducted from boat using established mooring buoys; depths start around 8 ft and extend to roughly 40 ft with some drop-offs beyond. Visibility is generally good, often 50–100 ft under favorable conditions, and water temperatures run about 70°F in winter to the mid-80s°F in summer. Currents are usually mild. The site is inside a Sanctuary Preservation Area where fishing and collecting are prohibited. Notable hazards include surface boat traffic and sharp coral, so good buoyancy control and situational awareness are important. The schooner USS Alligator grounded and was scuttled in 1822; only two piles of ballast stones remain from the wreck, and the reef structure has grown around those remnants.