Conceived as a watch for professional divers, the Sea-Dweller was launched in 1967. At the time of production, it was among the most reliable and robust diver's watches available on the market. Water resistant to 610 meters, its capabilities exceeded that of the Submariner. The watch featured a triple lock crown to ensure its water-resistant ability. The first examples, or "prototypes" displayed a single red Sea-Dweller script. It was only later, starting with the " Mk I Patent Pending Sea-Dweller Double Red" that the dial showed "Sea Dweller Submariner 2000" in two red lines, earning its moniker "Double Red Sea-Dweller".

While the first examples did not have a helium escape valve, Rolex eventually fitted their Sea-Dwellers with this mechanism, allowing the trapped helium to escape easily. When reference 1665 was first released, Rolex had not patented the technology yet. Thus, the earliest Sea-dwellers were engraved “Patent Pending Rolex Oyster Gas Escape Valve” on the caseback.

Among the very last examples produced, the present watch is fitted with a Mk IV dial, evidenced by the "closed 6" and the spiked coronet. This dial variation was among the last and was used until Rolex ceased production of reference 1665.

Its incredible “new old stock” condition matches, if not surpasses, that of the orangey deep patina dial, making it amongst the best-preserved examples appearing publicly in recent times. Turning the watch around, it still retains the factory green case back sticker and the fresh black ink around the case back should excite the most serious collectors. The present lot could be used to scholarly study how a 1665 case and bracelet appeared when originally delivered by Rolex. It is further enhanced by being a complete set, with an original box and punched guarantee paper.