Jules' Undersea Lab

Jules' Undersea Lodge in Key Largo, Florida is without question the world's most extraordinary dive-accessible accommodation — a former underwater research habitat that has been converted into a two-room underwater hotel where guests must scuba dive to access their rooms, sleeping and living beneath the surface of the Emerald Lagoon in a tropical mangrove lagoon at approximately 9 meters (about 30 feet) depth. Originally built as La Chalupa Marine Laboratory in Puerto Rico in the 1970s and used by National Science Foundation-funded marine researchers, the structure was relocated to Key Largo and opened as Jules' Undersea Lodge in 1986, operating continuously since then as the world's first and only true underwater hotel. Guests arrive at the lagoon, don scuba gear, and descend to the lodge entrance — a wet room that connects to the dry interior through a moon pool entry. Inside the lodge, two private rooms and a common area with kitchen facilities, entertainment systems, and round windows looking into the lagoon provide a genuinely habitable underwater environment at constant pressure. The experience of sleeping underwater — listening to the sounds of the reef, watching fish swim past the porthole windows in the night lights, and waking to the surreal sight of the lagoon exterior — is unlike any other overnight experience on earth. The surrounding lagoon is a rich mangrove ecosystem inhabited by snappers, tarpon, nurse sharks, and the diverse juvenile fish community typical of Florida's mangrove habitats. Jules' Undersea Lodge also operates as a dive center offering beginner introductory dives, aquanaut packages, and the ultimate overnight stay, making it accessible to non-technical divers in a carefully managed, safety-focused environment.