Rolex Sea-Dweller 1665

Sea-Dweller ‘Double Red’, Reference 1665 | A stainless steel wristwatch with date, helium escape valve and bracelet | Circa 1978 Rolex

Dial: black Calibre: cal. 1570 automatic, 26 jewels Movement number: D’533’474 Case: stainless steel, screw-down case back Case number: 5’389’728 Closure: stainless steel Rolex Oyster bracelet and folding clasp Size: 40 mm diameter, bracelet circumference approximately 195 mm (including additional links) Signed: case, dial and movement Box: no Papers: yes Accessories: Rolex Guarantee and two additional linksAimed at professional saturation divers who required a watch that could dive beyond the capabilities of most commercially available wristwatches, Rolex introduced a deeper diving but similarly designed big brother to the Submariner in 1969, named Sea-Dweller. Contrary to what is sometimes believed, the Sea-Dweller was the very first Rolex watch to feature an important innovation which allowed it to dive to an impressive 610 meters: the helium escape valve. Divers found with earlier watches that, as they ascended from great depths, the helium that accumulated within the watch would cause the crystal to pop off due to the decreasing pressure. Several brands began to formulate methods to combat this, with some engineering cases that were so sturdy that they would not be affected during the ascent, thus resulting in extremely bulky and impractical watches. Rolex engineered a more elegant solution; a small valve on the side of the case which releases any trapped helium, without impacting water resistance. The present watch belongs to the first product of this innovation, the Sea-Dweller reference 1665, the earliest examples of which feature two lines of red text on the dial. These early watches became known as the ‘Double Red Sea Dweller’ and are highly coveted. This watch belongs to the Mk. IV series, with non-italic depth rating, smaller ‘Submariner 2000’ text and distinctive coronet. An instantly recognisable aesthetic and rich history of technical diving innovation make this reference unmissable for any collector.