When Rolex introduced the Sea-Dweller in 1967, it represented an important development in the evolution of the professional diving watch. Although the Submariner had already established itself as an essential instrument for underwater exploration, the increasing demands of commercial saturation diving presented new challenges. Working alongside professional diving organisations, including COMEX, Rolex developed a watch capable of withstanding prolonged exposure to the extreme conditions encountered at depth. Central to its design was the helium escape valve, which allowed gas trapped inside the watch during saturation diving to escape safely during decompression. The Sea-Dweller ref. 1665 combined this innovation with a reinforced Oyster case, a substantial domed crystal and a depth rating of 610 metres, establishing a new benchmark for Rolex's professional diving watches.

The ref. 1665 remained in production for approximately two decades, during which its dial underwent several important changes. Early examples featured the distinctive red Sea-Dweller lettering, while the later generation introduced white printing throughout, giving rise to the collector nickname 'Great White'. Dating to 1981, this example features the desirable MK1 Great White dial, distinguished by its particular typography and arrangement of the four lines of text above six o'clock. The matte black dial is complemented by tritium hour markers and hands that have developed a closely matching creamy yellow tone, creating the balanced appearance prized by vintage Rolex collectors. Its 40mm stainless steel case retains the purposeful proportions of the original professional Sea-Dweller, while the folded-link Oyster bracelet completes the classic tool-watch aesthetic. Powered by Rolex's automatic calibre 1575, this example represents an important chapter in the transition from the earliest Sea-Dwellers to the modern professional diving watches that followed.