40 mm three-body waterproof stainless steel oyster case with screwed-down back and crown and a revolving black bezel for the decompression times.
Rolex cal. 1570
black with luminous round, triangular and baton indexes and aperature for the date
self-winding with date and a gas-escape valve
Condition: very good original condition
Description: The Sea-Dweller was designed for professional diving and was fitted with a one-way pressure relief valve on the side of thje case beside the nine o'clock position. This gas escape valve was patented in 1967 to allow the interior of a watch to decompress and avoid injury caused when the crystal of the watch pops during decompression after deep diving. This happens when the internal pressure of a watch is higher than the ambient pressure in a decompression chamber. This gas-escape valve helps during decompression, as the gas pressure inside the watch increased, that the gas in the watch can release the case.