Robert Pierre André Sténuit (born 1933 in Brussels) is a Belgian journalist, writer, and underwater archeologist. In 1962 he spent 24 hours on the floor of the Mediterranean Sea in the submersible "Link Cylinder" developed by Edwin Link, thus becoming the world's first aquanaut. Early career Sténuit began spelunking at the age of seventeen. He discovered diving in 1953, when he began scuba diving in flooded caves in Belgium. He subsequently became interested in speleology, and went on to spend many years exploring the Caves of Han-sur-Lesse. Sténuit had a passion for history. At the age of 20, after reading 600 Milliards Sous les Mers by Harry Reiseberg, a work of fiction about shipwrecks and treasure diving, Sténuit left the Free University of Brussels, where he was studying political and diplomatic science in preparation for a career as a lawyer. In 1954 Sténuit began looking for the treasures of the Spanish fleet sunk in 1702 at the Battle of Vigo Bay by English and Dutch warships. He searched without success, finding only modern wrecks. Together with another sunken treasure hunter, the American John Potter, Sténuit worked for the Atlantic Salvage Company, Ltd. on the specially-equipped vessel Dios Te Guarde for search and recovery of underwater treasure, beginning another search for the wrecks of the 1702 Plate Fleet, which lasted two years. Robert Sténuit worked as a professional diver for the French company SOGETRAM (Société Générale de Travaux Maritimes et Fluviaux), but eventually left SOGETRAM to become the chief diver for Edwin Link's Man in Sea project. Man in Sea project From September 6–10, 1962, Sténuit participated in Man in Sea, Edwin Link's first experiment with an underwater habitat, which was performed with a submersible decompression chamber (SDC) at Villefranche-sur-Mer on the Mediterranean, at a depth of 200 feet (62 m). While submerged in the cylinder, Sténuit breathed a helium-oxygen mixture (Heliox). The experiment was conducted from Link's yacht, the Sea Diver. Sténuit remained on the sea floor for over 24 hours, becoming the world's first aquanaut. During this dive, a mistral sank the Reef Diver, the Sea Diver'''s launch, which was carrying fifteen bottles of helium. A mistral surge also caused the cylinder to float back to the surface, where Sténuit remained safe from decompression sickness because the cylinder was still pressurized. A U.S. Navy boat brought an additional supply of helium during the night of September 7–8, allowing Sténuit