Launched in 1967, the celebrated Sea-Dweller reference 1665 was the first wristwatch designed for use in saturation diving. The HEV (Helium Escape Valve) – developed in the 1960s by Rolex in association with the French professional diving contractor COMEX - allows helium to escape the case during decompression. Often actively and intensively used, watches such as this are true tool watches, faithful companions for professionals doing one of the most technically difficult and risky jobs on the planet.

The present watch is an example of the ‘Mark III’ series of the Double Red Sea-Dweller dial, in production between around 1970 to 1973. Mark III dials are distinguished by a number of details: the ‘double red’ designation is written directly on the dial, without a white background print, and appears darker than that found on ‘Mk II’ dials. The "SUBMARINER 2000" designation presents smaller fonts than the "SEA-DWELLER" text. The five tips and the oval at the base of the Rolex crown are clearly defined. The overall impression of the fonts is thinner and less distinct than on the earlier versions.