Debuted in 1953, Blancpain's celebrated "Fifty Fathoms" model was presented as the first true modern diving wristwatch. The idea for the model arose when two captains of the French navy, Commander Maloubier and Lieutenant Riffand, requested a practical solution for a watch to be used by a new unit of military combat swimmers. Upon finding no existing watch capable of withstanding the extreme conditions of underwater missions, the two officers approached Blancpain with a very specific set of technical specifications, including the revolutionary unidirectional bezel. The watch developed following these requests is considered the archetype of the diver's watch, its name derived from the water resistance guaranteed to a depth of 50 fathoms or 91.45 meters.
In 1953, Blancpain signed a distribution agreement with LIP, the French watch manufacturer, the models available in France as of 1954 signed both Blancpain and LIP. The partnership between the two houses was ended in 1957, rendering these double-signed watches highly collectable.