Launched in 1967 in response to the rise of saturation diving – where a diver’s habitat is pressurised with helium and other gases on descent, the Rolex Sea-Dweller was the world’s first watch to incorporate a helium escape valve. By permitting the controlled release of helium from its case, the Sea-Dweller withstands decompression on ascent and is the perfect partner for deep-sea exploration, especially today with its 1,220-metre water resistance.