Sea-Dweller Ref. 1665 Rail dial



Iconeek is proud to introduce here a very attractive and rare self-winding, stainless steel, water-resistant, tonneau-shaped, diver’s wristwatch with date, sweep center second and first generation helium escape valve. The model is a reference 1665, from 1979, so called « Great White » by collectors, with the sought-after rail dial. The elusive Rail Dial White Sea-Dweller (or “RDWSD”) is a great opportunity for the savvy collector to acquire an extremely rare variation. With great history, remarkable evolution, rarity, the 1665 is a true icon in the world of diving’s wristwatch.

In late 1967, before the « HEV » patent had been accepted, a distinctive Rolex went into production as a specialized diving watch. Initially based on a thin submariner case, it led to the very desirable patent-pending Sea Dweller which was able to withstand depths of over 2000 feet or 610 meters. Regular production soon followed and the watch was produced with several different variations for the next forty years as model 1665, 16660 and 16600. A small batch of these Sea-Dweller was made to the specifications of COMEX, the company that originally helped with its development and testing. The “Sea-Dweller 2000”, Reference 1665, launched in 1971, was the first water-resistant watch to bear an helium escape valve for the decompression time indication, it is guaranteed water-resistant down to 610m./2000ft.  In 1974 the ref. 1665 Sea-Dweller was made with an all-white printed dial, such as the present watch. The words « Submariner 2000 » were no longer included on the dial.

The RDWSD is an extremely rare variation of the iconic « Great White » dial. According to the scholars, the model was in production for only two years only, between ’77 and ’79. This dial variation was manufactured by the Stern company, instead of the normally employed Singer. Stern Company, later owner of Patek Philippe, were at the time Rolex’s dial supplier. Some subtle differences are found on a « Rail Dial » compared the standard Great White. The name referred to the alignment of the white letters at 6. Most precisely, the last “E” of “superlative” and the “Y” of “officially” are perfectly aligned, as are the “C” of “chronometer” and “certified”. This creates a very pleasing and unusual vertical “gap”, a space between the lines of the designation on the left and those on the right. Another detail unique to the Rail Dial is the Swiss designation reading “T Swiss T < 25”: no other Sea-Dweller dial, including the Comex 1665 presents this designation. The correct serial number for a « RDWSD » is included between 5.7 million and 6.2 million. The present example featuring a case number 6’154’194 is offered in great condition. Rail dials are known also on other Rolex timepieces, most notably on the 1990s Explorer II ref. 16570, and are highly collectible.

The present model comes with a three-body construction: a water-resistant polished and brushed tonneau-shaped stainless steel Oyster case with first generation HEV in the band, crown guard for the Triplock crown, a hesalite crystal, a bi-directionnal revolving steel bezel bearing a black aluminum insert with decompression time, a screwed case back engraved «  ROLEX OYSTER Original Gas Escape Valve ». The case back is engraved inside « 1665 ». The serial number 6154194 is engraved between the lugs at 6, reference number 1665 is engraved between the lugs at 12. Under the glass, we find a superb condition matte black dial with painted luminous round, rectangular and triangular indexes, an outer minute and second division, luminous hands and sweep center second. Inside ticks a caliber Rolex 1570, rhodium-plated, with 26 jewels, straight line lever escapement, shock absorbers, Breguet hairspring, hack mechanism.  Dial, case and movement are signed.

While the “Great White” was only in production for five short years, collectors have identified four very different stylized dials. The present watch fitted with a « MK II » dial is the rarest dial among all four, characterised by the unique layout of the wording “Superlative Chronometer Officially Certified”, otherwise known as the “Rail Dial” by Rolex aficionados.

A collector per sure !

Condition: 8.5/10, in very good and original overall condition, a great addition to any diving watch collection

Brand: Rolex

Model: Oyster Perpetual Sea-Dweller Rail Dial, aka « RDWSD »

Reference: 1665

Year: circa 1979

Movement no.: D213574

Case no.: 6154194

Material: stainless steel

Dial: matte black, « rail dial », luminous hands

Movement:  cal. 1570, 26 jewels, hack mechanism

Functions: date, sweep center seconds, self-winding

Bracelet: stainless steel Rolex Oyster,  ref. 93150,  approx. overall length 180 mm.

Water-resistant: yes, tested

Dimensions: 40 mm. diam.

Accessories: fitted green presentation box

Ref. ICO: 99-20-034A

 In 1972, divers for Comex, a company specialized in underwater engineering, used the Rolex Sea-Dweller in a world record-setting, one and a half hour simulated dive down to 2000 feet. The watch performed so well that Comex decided to use only Rolex diving watches and chronometers in their work. In June 1972, divers Alain Jourde and Claude Bourdier again went down to 2000 feet, in an experiment which lasted 28 days. The divers remained at the lowest point, 2000 feet under sea level (610 meters), for 50 hours, a record-breaking feat, while wearing Rolex Sea-Dweller watches. At 2000 feet, the atmosphere contains a high percentage of helium gas, which can penetrate even a water-tight watch case. The gas cannot escape quickly enough upon resurfacing, and as the outside pressure decreases, the pressure remaining inside the watch due to the built-up gas can cause the watch to explode.

The Rolex Sea-Dweller watch was fitted with a special helium escape valve, aka H.E.V, allowing the gas to escape quickly during decompression. Invented by André Zibach, the patent no. CH491246A was filed in November 1967 and finally delivered in June 1970.