In the aftermath of the Second World War, the young French ensign Jacques-Yves Cousteau invented the aqua-lung with the help of Emile Gagnant, marking the start of the history of leisure diving. Clubs sprung up everywhere and the equipment improved. Jaeger-LeCoultre contributed to the development of this new sport by creating the first diving watch fitted with an alarm in 1959. The Memovox Deep Sea’s alarm served to remind divers that it was time to start their return to the surface. Memovox Deep Sea, model E857, a watch made up of 1060 pieces, created between 1959 and 1962. Jaeger-LeCoultre was to produce a replica of this legendary watch in 2011. One model to be sold by Artcurial was intended for the American market, as indicated by the LeCoultre signature. Long exposure to the sun has changed its colour slightly, giving it a chocolate tint, making it even rarer. Water-resistant to 100 metres, its steel case houses the Jaeger-LeCoultre 815 calibre, the first automatic alarm calibre in watchmaking history. The alarm time is indicated by a rotating inner disk.