Rolex implemented major changes to the Sea-Dweller starting in 1981. The sapphire crystal became standard starting with the Ref. 16660 and major developments were implemented into the model which included a uni-directional bezel as opposed to the bi-directional bezel found in previous examples, a larger and more reliable helium escape valve was added, and we see the introduction of the first solid end link (SEL) bracelets with the Ref. 93160 bracelets with attached 592 end links becoming standard around 1981-1982. The Sea-Dweller also received a new movement, the Cal. 3035 which allowed for Quick-Set date function.

In the early 1980s Rolex was working very closely with the Compagnie Maritime d' Expertise Company (COMEX) to develop a tool watch to accompany the company's divers who started to work at deeper depths as a result of the increasing mixed gas diving standards of early 1980s and the Ref. 16660 is a perfect example of the two company's partnership to achieve a tool watch to meet specific needs.

CASE & BRACELET

The unpolished case retains strong crown guards, case finishing, and chamfers while exhibiting honest signs of use. The original bezel insert displays some light signs of use and has taken on a desirable navy blue coloration. The case back retains all of its original factory markings in deep and legible condition. The Rolex 93160 Oyster bracelet with integrated divers extentions retains 10 links and exhibits some stretch which is common for this style of bracelet.

DIAL & HANDS

The glossy black dial is in superb original condition showing no blemishes or signs of age. The tritium lume plots remain bright white in coloration and show no degradation when inspected under U.V. light. The original tritium hands match the dial perfectly and exhibit no degradation under U.V. light inspection.

ACCESSORIES 

None. The watch was recently serviced and is keeping time within COSC spec, back by a 1-year warranty on accurate timekeeping.