Lot Essay
The present watch is from the forth, so-called "Mark IV" or "MK4" series of the "double red" Sea-Dweller, in production between approximately 1974-1977.
The celebrated Sea-Dweller reference 1665 launched in 1967 was the first wristwatch designed for use in saturation diving, fitted with a Rolex patent valve in the band and guaranteed waterproof to 610 meters depth. The valve was first developed on the Submariner model and allows helium and other gases to escape, enabling the watch to withstand compression.
The celebrated Sea-Dweller reference 1665 launched in 1967 was the first wristwatch designed for use in saturation diving, fitted with a Rolex patent valve in the band and guaranteed waterproof to 610 meters depth. The valve was first developed on the Submariner model and allows helium and other gases to escape, enabling the watch to withstand compression.