Released in 2008, the Rolex Sea-Dweller Deep Sea served as the replacement for the regular Seadweller until the introduction of the Seadweller 4000 in 2014. It features a heavy stainless steel case of 44mm with a titanium insert in the caseback. Another notable change is the crystal, which is domed instead of flat - resembling the look of the old 1665's.
This model is equipped with calibre 3135, a self-winding mechanical movement entirely developed and manufactured by Rolex. Like all Rolex Perpetual movements, the 3135 is a certified Swiss chronometer, a designation reserved for high-precision watches that have successfully passed the Swiss Official Chronometer Testing Institute (COSC) tests. It is fitted with a Parachrom hairspring, offering greater resistance to shocks and to temperature variations. Its architecture, in common with all Oyster watch movements, makes it singularly reliable.