SEA-DWELLER MODEL, REF. 1665 “DOUBLE RED”, CIRCA 1975

Launched in 1967, the Sea-Dweller reference 1665 was the first Rolex wristwatch designed for use in saturation diving. It featured a Rolex patent valve in the band, first developed on the Submariner model, to allow helium and other gases to escape, which would enable the watch to stand compression at deep depths.