Launched off the coast of Marseille in December 1981 at the exact same place where the first underwater habitat Précontinent of the commandant Cousteau in 1962, Hippocampe I was tested by Jacques Rougerie and Bernard Gardette, psychologist of Comex, during an underwater demonstration on the subject of the offshore industry. Suspended midwater following the principle of the Galathée, the aluminum structure has broad methacrylate “windows” open under the sea, inserted in the aluminum set that could host 2 people in saturation conditions at less than 12 meters for the period of 7 to 15 days. After this first experiment, Hippocampe I joined the Mexican Yucatan under the lead of Armando Ferrat who continued experimenting with the underwater life off the coast of Cancun, in Isla Mujeres, where the vessel is now exhibited.