The second generation of Seamaster Pro GMT watches shifted focus back to being a dive watch and in doing so became the basis of one of the most significant and rare military unit limited editions ever made.
A Simplified Successor to the Seamaster GMT
The original Seamaster Pro GMT was a watch with many fans and quite a significant following for the quality, style and functionality offered at a very modest price-point. There's an article going over this Cal 1120 based pre-Co-Axial version here which explains it in depth.
For the second-generation Co-Axial version, there was only one choice of color-way and design, with the GMT being a minimally modified version of the 2220.80 Bond Seamaster Pro. In doing this, Omega removed the GMT bezel, deeming it less useful than the 60-minute dive bezel. This left the watch with a GMT function and diving ability but as less of a travel watch and no longer a competitor to the Rolex GMT-Master line.
The reception to this watch was rather interesting, it definitely fell out of favor with those that were fans of the original GMT who were dismayed that this watch felt like a bit of a step backwards. Then at the same time, the Seamaster Pro 300M GMT found a new group of fans who liked the Bond Seamaster Pro or dive watches in general and wanted the addition of a GMT or home-time function.
Over the years that would follow, Omega continued to oscillate between offering GMT watches with a dedicated 24-hour bezel, and with a dive bezel until finally settling on their current solution; offering both and letting the customer choose.
The Royal Navy Special Boat Service (SBS) Limited Edition
Omega is famous for supplying Seamaster 300 Big Triangle divers, RAF53 pilot's watches, and other military issued models to the British Ministry of Defence, and in recent years has supplied many small volume limited editions to individual units.
The Ref 2539.80 Seamaster Pro 300M GMT SBS Limited Edition of 500 units is a particularly significant and fitting example. This watch is based on the standard Ref 2535.80 Seamaster GMT but instead of the transparent display-back of the regular model, Omega has fitted a sapphire display-back painted on the inside with the SBS insignia and motto.
Given the nature of the Seamaster Pro GMT and the SBS it makes a lot of sense that this particular watch would be chosen as their limited edition, as it has all of the features including elapsed timing bezel of the regular Seamaster with the addition of Zulu time on the dial.
As mentioned, these watches were produced as a limited edition of only 500 units, which is actually more than would have been needed as the SBS is estimated to have only around 200-250 commandos. Presumably by making a larger number, these watches could have been held in reserve for future SBS members on an as needed basis.
A Set Sold For £5,000 By noonans.co.uk In Mid-2021 - An Excellent Deal
These watches were not made available brand new to the public by Omega, only members of the SBS were able to purchase them. It is however possible to buy these watches on the secondary market, where they carry a slight premium over the regular version as SBS members have chosen to sell them over the last decade.
There is nothing wrong with buying these watches used, appreciating and wearing them even with the SBS patch on the case-back so long as you're honest about how you acquired one. Most SBS members would likely be reluctant to part with their Seamaster unless genuinely necessary so seeing them get their money's worth for their watches used is definitely not a bad thing.
The Royal Navy's Special Boat Service
The Royal Navy's Special Boat Service can trace its origins back to 1940 in the middle of World War II, evolving through many forms and names before receiving the designation "Special Boat Service" in 1987, having taken on maritime counter-terrorism responsibilities.
The SBS is the maritime special forces unit of the Royal Navy, effectively that branch's equivalent of the British Army Special Air Service (SAS). The SBS cap badge and motto, "By Strength and Guile" featured prominently on the Limited Edition SBS Seamaster's case-back were adopted not long before the production of the watch in 2003.
The vast majority of the SBS's activities are highly classified and not commented on by the British government, however it goes without saying that they play a crucial role in the protection of the nation and its interests.
Where the SBS and the Bond Seamaster intersect, is that Bond author Ian Fleming was himself a Royal Navy intelligence officer, holding the rank of lieutenant commander. During his service, Fleming proposed the creation of the commando unit 30AU, which he would go on to direct in their intelligence gathering operations from the rear. Fleming's experiences and interactions with these commandos would go on to form the basis for the author's eponymous spy, James Bond.
While the backstory of Bond has changed slightly over the years to fit with current events, what remains constant is the fictional character's origins as a Royal Navy officer and commando. When the franchise rebooted with Daniel Craig for Casino Royale, the official narrative was that Bond became a "double-0" agent for MI-6 after serving in the SBS.
While James Bond is a fictional character of Ian Fleming's imagination, countless young men have been inspired by the stories and movies over the 70 years since Dr. No first hit the shelves in 1953. Similarly, Fleming himself was so inspired by these British commandos, that the greatest action character of the last 100 years was directly inspired by their exploits and actions.
Case & Bracelet
The Seamaster Pro 300M Diver GMT Co-Axial case follows the same overall design as the Seamaster Pro going back to the original 2531.80 of 1993, however it has grown larger over the years with both the move to Co-Axial movements and slightly more due to the GMT complication.
The Seamaster Pro 300M Diver GMT Co-Axial SBS Edition Ref 2539.80 - Image by thewatchbox.com
The regular 2220.80 Seamaster Pro 3-hand watch is a very svelte 12.5 mm thick while these GMT Seamasters are 2 mm thicker at 14.5 mm. It does carry it well and with the quite substantial Bond bracelet, the head of the watch never feels excessive or heavy.
One further difference between these Co-Axial GMTs and the prior Seamaster Pro GMT is that this model has the helium escape valve in the 10 o'clock position given the diving focus of the watch, while the previous GMT models omit it. This generation continues to use an aluminium bezel insert, which can be scratched and damaged fairly easily, and unfortunately there is no replacement insert with only an entire bezel assembly available from Omega.
The Display-Back On The Standard 2535.80 Seamaster Pro GMT (Left) & The SBS Painted Case-Back (Right)
The case-back on these GMT models is exclusively a display-back unlike the regular 2220.80 which has a solid steel case-back with a large hippocampus relief. Despite the use of the display-back, both the GMT and SBS Limited Edition maintain the same 300 meters water resistance.
Both the Ref 2535.80 & 2539.80 come exclusively on the stainless steel "Bond bracelet" with no rubber strap or alternate bracelet style available. The lugs are a standard 20 mm width however, so there is no difficulty in fitting an Omega or aftermarket rubber strap, NATO or even some alternate bracelets.
The Seamaster Pro 300M Diver GMT Co-Axial On Bracelet (Left), Leather Strap (Center), & Rubber Strap (Right)
Movement
The movement powering both versions of the Seamaster Pro 300M Diver GMT is the Co-Axial Calibre 2628, including both the 2628A and 2628B variants.
The Cal 2628 is derived from the Calibre 2500 movement used widely in Omega's product range including by the rest of the Seamaster Pro and Planet Ocean models, with the only significant difference being the addition of a GMT hand on the Cal 2628.
The Cal 2628 does suffer from the difficulties had by early versions of the Calibre 2500 movement family. Early versions of these movements used the "two-level" version of George Daniels' Co-Axial escapement, intended to be more vertically compact than the "three-level" version which Daniels initially designed. Ultimately the "two-level" escapement went through several revisions both in the design of parts and in servicing procedures before Omega switched to using the "three-level" design from the Calibre 2500D onwards.
There is a lot of information on the various versions of Calibre 2500 family floating around the internet, much of which is not entirely correct. The Calibre 2628 was released during the production of the Calibre 2500B variant, so the Cal 2628A is roughly the GMT version of the Cal 2500B, oscillating at 28,800 vph. The revised Cal 2628B is thus the GMT version of the Calibre 2500C, oscillating at a reduced 25,200 vph. There is no C variant of the Calibre 2628 featuring the three-level Co-Axial escapement as is found in the Calibre 2500D, as these movements were withdrawn from sale by such time.
At the end of the day, if you have one of these, or purchase one, take it to be serviced by an Omega qualified watchmaker and they will be able to implement the latest upgrades and servicing procedures to ensure that the escapement does not create problems in the future. Once serviced, enjoy the watch and don't worry.
Dial & Variants
The Seamaster Pro 300M Diver GMT Co-Axial is a significant upgrade in finishing quality over the previous generation especially where it comes to the dial.
Unlike the 2220.80, where a rhodium plated white gold applied Omega logo is used, the GMT variant retains a painted logo, but with applied hour markers and red GMT text. The reason for the lack of an applied logo is because the GMT hand is the lowest on the stack and sits so close to the dial that it would foul against the Omega logo if it were raised from the surface. Suffice to say this is a technical reason and not an oversight on Omega's part.
In place of the GMT bezel are painted markings in 8 locations inside of the hour markers. This does limit the flexibility of the watch somewhat but will suffice for many users still. The red GMT hand itself is quite subtle, and sitting below the other hands does not get in the way of timing dives.
The balance of the dial is effectively the same as the 2220.80 with the familiar wave pattern, date window and layout. This was the final generation to have the much-loved wave dial so that's something worth keeping in mind also.
This dial is used for both the 2535.80 standard and 2539.80 limited edition models.
The Standard Seamaster Pro 300M Bond Co-Axial GMT Ref 2535.80
The regular version of the Seamaster Pro 300M GMT Co-Axial carries the reference 2535.80 and features a sapphire display-back, revealing the decently decorated Calibre 2628 Co-Axial movement.
The Limited Edition 1/500 Special Boat Service Seamaster GMT Ref 2539.80
The SBS version of the Seamaster Pro 300M GMT Co-Axial carries the reference 2530.80 and features a fully painted, opaque sapphire display-back, hiding the movement from view.
Buying
The big decision with these watches is do you want just a regular Seamaster Pro GMT or do you want to spend the time and money to hunt for one of the rare SBS limited editions in circulation.
The regular 2535.80 Seamaster Pro Co-Axial GMT is a watch that spent a decent amount of time in production and was sold in fairly high numbers over that period. As a result, there is a very large supply of these watches available everywhere from eBay to Chrono24 to forums. Price wise these are hovering around the $3,000 level which is not unreasonable for a GMT watch of this quality, even considering the cost of a service.
The SBS Limited Edition 2539.80 is both very tough to find and very tough to accurately value. There is currently only one for sale, which has been sitting on the market for 10 months now at $18,500 which is a massive premium over the regular version. In recent years though, these watches have sold for as low as $4,500-5,000. It should be remembered that these are not issued watches per-se, but are commemorative limited editions available for purchase, and while still significant and very cool they should be valued accordingly.
Condition wise, the first priority on these watches is the bezel which will be costly to replace due to only being sold as a complete assembly rather than just an insert. The case and bracelet should be as clean and free of scratches or dents as possible. Due to the high water resistance of these watches, dial and hands should be perfect and any sign of damage or moisture intrusion is a deal-breaker. Due to the age of these watches, all of them are now due or overdue for service, so this should be assumed as part of the service price and timing performance shouldn't be a major issue as a result.
The Seamaster Pro Co-Axial GMT was the final Seamaster Pro 300M model to feature a GMT complication. Following its retirement only Planet Oceans and chronographs would continue to offer it moving forward, which is a shame really. These watches were accurate, thin, highly capable diving-oriented GMT watches with a great story and appreciated by some of the toughest men to ever serve.
Discussion thread on Omegaforums can be found here:
