Jules’ Undersea Lodge occupies a category of one. There is no other property in the world that requires guests to put on scuba equipment, descend into a lagoon, and enter their accommodation through a moon pool in the floor — and yet the lodge has been doing exactly this in the mangrove lagoon of Key Largo Undersea Park since 1986, making it the world’s first and longest-operating underwater hotel.
The structure began life as La Chalupa research laboratory, a scientific habitat used by researchers studying the Florida Keys marine environment in the 1970s. Converted to its current purpose in 1986, it sits on the lagoon floor at approximately six metres depth, anchored to a weighted base and supplied with breathable air pumped continuously from the surface. The interior — pressurised to prevent water entry through the open-bottomed moon pool — consists of a main living area with a kitchen, dining table, and the porthole windows, plus two separate sleeping cabins. The portholes are circular, roughly 45 centimetres in diameter, positioned at eye level from a seated position. Through them, the lagoon’s residents are in constant view: sergeant majors, damselfish, the occasional barracuda, grouper drifting slowly through the structure’s shadow, and the various species that have colonised the exterior during the decades the lodge has been on the bottom.
The dive requirement is central to the experience, and to the kind of guest it attracts. Non-certified divers complete a three-hour orientation before their descent, and the repeated act of entering and exiting the lodge is itself a meaningful part of the stay. Waking at 3am in an underwater room, pulling on a wetsuit, and slipping through the moon pool into a lagoon lit only by bioluminescent plankton and distant surface light is something a very small number of people on Earth have done. It remains among the more genuinely extreme accommodation experiences available.
The practicalities are managed with good humour. Meals are delivered by diving couriers from the surface kitchen — the underwater pizza delivery is among the lodge’s most celebrated features. The sleeping cabins are snug but functional, the showers run hot, and the sound of small fish investigating the porthole glass makes for an unusual but entirely effective aid to sleep.
