Debuting in 1967, with the specific aim of bolstering Rolex's dive watch offering, the Rolex Sea-Dweller built upon the industry-leading dive watch credentials that the Submariner had earned Rolex over the previous 14 years. Created specifically with professional divers in mind, Rolex collaborated with diving companies like COMEX to perfect the Sea-Dweller's design and ensure it would be the ultimate dive watch. Featuring the ingenious Helium-Escape Valve that Rolex had patented the same year, a hugely impressive water resistance, and a sizeable case design, the Sea-Dweller rightfully toppled the Submariner as Rolex's most hardcore dive watch. Today offered in a few separate styles such as two-tone, with various dials, and in two different case sizes (43mm and 44mm), the Sea-Dweller has taken a leaf from the rest of Rolex's offerings and merged its tool-watch focused design with tasteful aesthetics, to create one of the most sought-after and best-equipped dive watches that any diver might ever need.

Watch is in excellent overall condition. Watch appears to have been recently polished, and at the edges are sharp and chamfered, with no visible scratches or dings. Bezel insert has a few marks as shown in the images. The dial is in excellent condition. There is a few areas of oxidation on the surface, specifically around the date window. The luminous dots and hands have aged to a dark yellow color. Bracelet has 14 links with 4 removable links. There is little stretch.

A transitional model of sorts, the ref. 16660 ushered in a new era for the Sea-Dweller as it modernized the collection with its new movement and crystal, increasing its robustness and ability to perform to the highest standard as its wearers often needed.