Mastering decompression with the helium escape valve
In order to overcome this problem, in 1967 Rolex introduced the Sea-Dweller, a divers’ watch with a helium escape valve. It is screwed to the case and consists of a hermetic cylinder, a piston, a gasket and a spring, acting as a safety valve. When the internal pressure in the case is too high, it opens automatically, allowing the helium atoms to escape.