SOLD-Rolex Oyster Perpetual Seadweller 16600 box and papers

First introduced in 1967, the Rolex Sea-Dweller has an illustrious history. It was created for the divers of deep sea diving specialist COMEX, and the first watch to have a helium escape valve. So the Sea-Dweller ref. 16600 was mourned when it was discontinued in the late 2008 and replaced by the very much larger Deepsea.

In the late sixties COMEX started pioneering a new method of diving called "Saturation Diving" which allowed divers to stay submerged for much greater lengths of time. Saturation diving is a diving technique that allows divers to reduce the risk of decompression sickness ("the bends") when they work at great depths for long periods of time. When divers dive into the great depths there is always a danger of decompression sickness which occurs when inert gas that had been absorbed by the body forms bubbles under the pressure of decompression. These bubbles can then block blood vessels or damage nearby cells. By having the divers breathe a mixture of helium, hydrogen and oxygen in their tanks and then having them breathe the same mixture in a pressurized underwater environment, the divers can last for days (or even weeks) underwater and only resurface once at the end of the dive, thus reducing the risk of the bends significantly. However, the human body is much more adept at disposing of helium than a watch case is. The divers found that helium molecules would pass through the seals of a watch and expand. Violently. Imagine a champagne cork but made of the crystal of a watch. Not what you want to be happening hundreds of meters underwater in a small capsule.

By the end of the decade COMEX aimed to send divers down to depths of 300 meters (1,000 ft+), 100 meters deeper than the highest rated Submariner or Seamaster could handle. This objective was the motivation for the Rolex Sea-Dweller and Omega Seamaster 600. Both brands took up the challenge to produce the best watch for saturation diving.

Omega designed a Omega decided to completely start afresh from anything they had made before and it took four years of development to produce the Ref. 166.077, the Omega Seamaster 600, in 1970. Their original plans had been to fashion a watch using titanium (10 prototypes had already been made) but titanium was very expensive to buy and very difficult to machine. Instead of titanium, Omega developed a solid stainless steel mono-block case; by forgoing the removable case back, the only two points of entry for water were the crown and the crystal. After chemical treatment to make it anti-reflective and anti-abrasive, a 4mm thick mineral crystal was tested at being able to withstand pressure of up to 60 atmospheres. If you look at the crown on the Seamaster 600 you could be forgiven for thinking that it is square, however this is just a shield that would stop the crown from unwinding accidentally under pressure. Due to the large crown guards and this extra cover, Omega decided to place the crown at the 9 o'clock position so divers could move their right hand free from obstruction. The name PloProf actually came from the French divers who used the Seamaster, Plongeur Professionel, Plo. Prof. Rather than the standard uni-directional bezel, the bezel on the Seamaster was bi-directional and was activated by pushing the orange button located on the side of the watch.  

Throughout the years there have been pieces of technology that have gone far above and beyond the call of duty. The PloProf is one of those pieces. It. is. insane. When Omega first launched the Seamaster 300 in 1957, it was actually only water resistant to 200m and was only called the 300 because it sounded better. So it was a reverse twist of fate that the PloProf was actually tested under far stricter conditions than its claimed 600m. Tested to a simulated depth of 1370m, the only reason the watch wasn't tested further was that the glass expanded and had jammed the second hand stopping the watch. Once the pressure subsided the movement started working perfectly again. Whilst Rolex had opted to go for a more high-tech approach, Omega instead went for sheer brute force (very well engineered and brilliantly designed brute force, mind). Not that I think it was a bad approach, as in fact I prefer the sheer nonsense of the PloProf over the more refined and technically advanced Sea-Dweller.  At the time the PloProf was Omega's most expensive piece, but I doubt that they ever recouped the cost of development even with a nine year production time. For the general public its unwieldy size of 54mm by 45mm was just too huge. Even today it's considered a beast, so think what it must have been like back in 1970!

I think it would be a fair assessment of Rolex to say that they are the more conservative of the two companies. Whilst Omega was designing a completely new piece that would just tough it out against helium, Rolex decided on a more elegant approach and took to modifying an existing Submariner reference, the 5513. It is interesting to note that on the Rolex website they write that making a watch impervious to helium is "a practically impossible task". Obviously no-one told them about the PloProf! What Rolex developed would soon become the standard for all professional diving watches thereafter, the Helium Escape Valve or HEV. By having a uni-directional valve on the side of the watch, it would allow the small helium molecules to exit the watch without causing any damage. In November of 1967 Rolex applied for a patent for the HEV valve but released the new Ref. 1655 anyway, two years before the patent was granted.

Source: https://www.timepiecechronicle.com/features/2015/8/25/the-call-of-the-sea-the-omega-seamaster-600-vs-the-rolex-sea-dweller

This Rolex Seadweller is model number 16600. This series has been made from until 1989 until 2008. Launched in the late 1980s, the reference 16600 is virtually identical to the late “Triple Six,” maintaining its sapphire crystal and its 1,220 meter water resistance. Over its remarkably long production period, the luminous material evolved from tritium to Luminova, and then to SuperLuminova. You can easily tell which is which by looking at the bottom of the dial – T Swiss T<25 indicates Tritium, Swiss indicates Luminova, and Swiss Made indicates SuperLuminova.

The reference 16600 also utilizes the caliber 3135, a slightly improved version of the caliber 3035. It has a longer power reserve and a full-fledged balance bridge, instead of the balance cock. The reference 16600 was discontinued after 20 years in Rolex catalogs, making it the longest lasting Sea-Dweller reference, and an easy model to find pre-owned. As with modern watches, a full set (with original box and papers) is preferable to a “naked” watch, even if it means paying a small premium (in the case of vintage watches, this premium can be drastically higher given the considerable time since the production of the piece).

The later reference 116600 (2014-2017) differs most distinctively from the 16600 because it got bezel upgrade to Cerachrom ceramic instead of the aluminum.

This watch has undergone a recent service and has been lightly cleaned and polished to look as good is possible. The watch was originally sold 18^th May 2006 and has a D9691** serial number.

So why should you buy this piece? The Sea-Dweller I Submariner on steroids! It has been developed for the saturation divers of COMEX. The watch also incorporated a helium release escape valve for gas decompression chambers. This model also lacks of a cyclops —date loupe— providing a cleaner and more simple look in comparison with its sibling the Submariner Date. The 16600 is the last Seadweller with aluminum bezel. Its resembles a lot of the watch introduced in 1967 but this one has the best reliability one could think of. If you put it on your wrist, you feel you have locked and Wrist Icon!