The deepest known reef off the continental United States, Pulley Reef is a 100+ km-long series of North-South trending, drowned, barrier islands located in the Southeastern Gulf of Mexico, near the edge of the Florida Continental Shelf. The reef is located approximately 150 miles southwest of Naples Florida and 60 miles northwest of the Dry Tortugas Ecological Reserve. It lies approximately 84 m below the ocean surface. The shallowest parts of the ridge are about 60 m deep. Even at these depths, there are many species of zooxanthellate scleractinian corals, green, red and brown macro algae, and shallow and deep water reef fishes.