Designed to endure the harsh environment of deep sea exploration, Rolex in close collaboration with COMEX, (Compagnie Maritime d’Experises, a French diving company) had a long relationship in creating historically important timing instrument under extreme depths. First introduced to the public in 1967, the Sea-Dweller ref. 1665 features a helium escape valve to release pressure during expeditions of deeper depths.

Following the coveted Double Red Sea-Dweller ref.1665, Rolex introduced the “Great White” variant. Notable for its all white “SEA-DWELLER” text and the absence of “SUBMARINER 2000” designation, hence the nickname “Great White”, this is the very first time the Sea-Dweller exist as a lineage of independence rather than an extension of the Submariner 5513.

Further enhanced by its rarity, the present example is what collectors known as the MK II rail dial variant of the reference. With production for only two years between 1977 to 1979 with a serial number between 5.7 million to 6.2 million, the dials were made by the Stern Company instead of Singer. Elusive and highly collectible, the Rail dial can be distinguished by the subtle details. The “C” of chronometer lines up with the “C” of Certified creating an unusual yet pleasing vertical corridor or rail between the last two lines of the designation is what gives the dial its nickname. It’s worth noting that the MK II variant is also the only Sea-Dweller that bears a “T SWISS T <25” amongst all variants.

The present specimen featuring a 5.9 million serial is most definitely a desirable and rare one. Well-preserved and in great proportions throughout, furthermore the luminous material has gained a warm yellow patina enhancing its vintage appeal.