Although the Submariner is Rolex’s most famous and best-selling dive watch, Rolex also produced two other watches designed specifically to conquer the depths of the ocean that surpass the Submariner in terms of performance. Originally conceived in the 1960s, the Rolex Sea-Dweller was a line of ultra-capable professional dive watches designed to take over from the Submariner, enabling users to dive deeper and stay at depth longer. 
The Rolex Sea-Dweller line includes the standard Sea-Dweller and its more extreme sibling, the copy Rolex Deep Sea-Dweller. While the Deep Sea line holds the title of Rolex’s most water-resistant watch, both are among the largest and most capable dive watches Rolex has ever released. While they were both designed for similar purposes, the Rolex Sea-Dweller and the Rolex Deepsea are surprisingly different watches.
Between the classic Sea-Dweller and the Deepsea, the entire Rolex Sea-Dweller collection currently consists of four watches. The classic Rolex Sea-Dweller is available in stainless steel (Ref. 126600) and in two-tone steel and 18-carat yellow gold.
Although the Sea-Dweller is traditionally a 40mm watch, the size of the most recent generation of Sea-Dweller watches has increased to a case diameter of 43mm. In addition, while previous versions of the Sea-Dweller have traditionally had a flat crystal, the latest generation has added Rolex’s signature Cyclops magnifying glass to the crystal face. With the exception of a few minor details on the dial and bezel, the latest generation of the Rolex Sea-Dweller largely resembles an enlarged version of the contemporary Rolex Submariner.
Both the previous generation replica Rolex Sea-Dweller and the Rolex Deepsea were powered by the tried-and-true calibre 3135, which has been used to power most of Rolex’s date watches since the late 1980s. However, in 2017, Rolex began updating its various Sea-Dweller watches with its new generation of in-house date display movements, the Caliber 3235.
Despite the differences, today, all Rolex Sea-Dweller and Deepsea watches are equipped with the Caliber 3235. Protected by 14 patents, the 3235 movement has a 70-hour power reserve and also features Rolex’s new, highly efficient Chronergy escapement, in which the redesigned pallet fork and escapement wheel are made of nickel-phosphorus and are insensitive to magnetic interference.
