The Sea-Dweller’s Oyster case, guaranteed waterproof to a depth of 1,220 metres (4,000 feet), is a paragon of robustness and reliability. It is fitted with the helium escape valve, patented by Rolex in 1967. This safety feature allows excess pressure built up in the watch case to escape during a diver’s decompression phase in a hyperbaric chamber, while preserving the waterproofness of the watch. The new version of the Sea-Dweller is equipped with calibre 3235, a new-generation movement entirely developed and manufactured by Rolex.