The Rolex Milsub: the MIL-itary SUB-mariner

Written by:Alessandro M.|

Those who love vintage watches will almost certainly have come across a military watch that has caught their eye. Whether they were on the wrist of a solider on the front-lines or worn by an Army Officer planning battle tactics, military watches hold a special place in the history of horology.

There are plenty of types of military watches, but I find that the best way to categorise them is by branch of the Armed Services (Army, Navy, Air Force, etc.), as the function they were meant to serve played a hugely influential role in the form that they took. For example, a watch assigned to Fighter Pilot will greatly differ to that of a Naval Diver, simply because they need to carry out different tasks.
One thing is common to all military watches, though: nomenclature and numeration. This is most commonly found on the caseback, and reveals tons of infomation – principally who it was commissioned for and when.

In this article, we’d like to talk to you about one of the rarest and most sought-after military watches of all time. They hold this title not only because it was manufactured by the world’s most famous watchmaker, but also because it was a non-commercialised watch, which, consequentially made it “exclusive” and very limited in terms of production numbers. Today, only a handful of finely preserved exemplars remain.

The most famous military diver’s watch of all time…

We are talking about none other than the Rolex “Milsub” (MIL-itary SUB-mariner): a watch which saw roughly 1200 units produced, 180 of which are known to have survived the test of Armed Service and time in general. Of these 180, extremely few are totally coeval.

By “coeval”, we mean that they are totally original: it was never subject to any replacement components when serviced.

The Milsub was the result of a collaboration between the British Ministry of Defence (MOD) and the famed Genèvese watchmaker at the turn of the 1970s. The task was to design and build a robust and reliable watch which was to be perfectly legible at profound depths. This watch was to be worn by British Divers for military purposes.

The iconic reference

Rolex was (and to this day is), without a shadow of a doubt, an industry leader when it came to special waterproof “Divers” watches, and it was for this very reason that the British MOD placed their trust in them.

Just as a quick note whilst we’re here: it is widely accepted that the Submariner and the Sea-Dweller are two of the most famous Diver Watches of all time. At IWS, we’ve produced extensive and comprehensive articles on these models, which you can learn all about using the following links. They could serve as great background reading for this article!
Rolex Submariner “Red Writing”
Rolex Submariner “White Writing”
Rolex Sea-Dweller
The First Diver Watches in History

In order to fulfil the MOD’s needs, Rolex decided that, rather than creating an entirely new watch, it was best to build upon an already tried-and-tested pillar: the Rolex Submariner Ref. 5513.

The fixed lugs

To increase the overall robustness and toughness of the watch, Rolex decided to incorporate fixed lugs on the Milsub. This made it exclusively wearable with a military-grade NATO strap.

This decision was also made to limit how “shiny” the watch was: if it had a steel bracelet, the watch would have a larger reflective surface area, which could have given away one’s position and movement – a potentially dangerous mistake.

The bezel insert and the hands

In order to tick the legibility box, something of utmost importance when it came to the MOD’s request, two very significant modifications were made to the Milsub. Firstly, a specially-designed bezel with 60 minute graduations (i.e. all the way around) was employed. Second, the standard “Mercedes” style hands were replaced by “gladio” (similar to Sword) hands.

The famous “T” stamped dial

Moving on, you will also notice that the Rolex Submariner Milsub sports a bold and encircled “T” just below the centre of its dial. This stamp was used to indicate that the luminescent material that was used for this watch was Tritium, and not Radium (which was what was used as standard by Rolex at the time).

Credits: Stefano Mazzariol

Nomenclature and Numeration

As previously mentioned, like any and all military watches, the Milsub’s caseback is engraved with special numbers, letters and sometimes symbols, which reveal all sorts of interesting information. The way they are classified is as follows:

  • 0552: designation of the SBS (Special Boat Service), the elite divers of the British Royal Navy;
  • 923-7697: special code used by NATO’s numbering system for watches that were destined for acquatic roles;
  • The “Broad Arrow”: this symbolises the watch’s grander association with the British Armed Services;
  • 395/75: soldier identification number (395) and year of assignment (1975).
    (Tudor’s Military Submariners had a similar system for this last one!)


  • This wasn’t the first time that Rolex was at the service of the British Ministry of Defence (MOD): towards the end of the 1950s, the MOD commissioned the crowned watchmaker for a watch for their divers. Rolex decided to use the ref. 6538, which, after some military-grade adjustments became the ref. 6540. After realising that only 21 pieces would needed to be produced, this decision was “reversed” and renamed the ref. A/6538. On the aftermarket, you can find some extremely rare Rolex Sumbariner ref. 6540s whose casebacks display a line through the “6540” and an additional “A/6538” engraving. The timepiece pictured below is thought to be the only totally original (coeval) exemplar in the world.
  • Between 1967 and 1971, the MOD’s official diver watch was the Omega Seamaster 300. From 1971 onwards, it was the Milsub.
  • The Milsub was actually produced across 3 references: the 5513 (first batch), the 5513/5517 (“double-barrelled” number made in the second half of the ’70s) and finally the 5517 (last batch).

On the market

Considering the fact that the Milsub is perhaps one the most well-known military watches of all time, paired with the difficulty of finding one that hasn’t undergone any replacements, it comes as no surprise that they have an astronomical asking price.

The Milsubs are held to such a high standard, too: a single component substitution could very significantly change its value. For example, replacing the original bezel with even a period-correct one diminishes the watch’s value by €20,000 alone!

Just to give you an idea as to how valuable and sought-after a Milsub is, one of the most recent Phillips auctions which featured a Milsub fetched a hammer price of €176,000 for just the watch by itself.

More recently, in December of 2019, a “double-barrelled” (ref. 5513/5517) Milsub went up for auction. This exemplar was in perfect condition: it even came with the Royal Navy’s certification document and the diving knife belonging to the soldier that the watch was assigned to! This one was auctioned for €184,000.

-Translated by Patrick R.


Est. 1993. Mechanical Engineer since 8 years now. He fosters a great passion for watches and the vintage world specifically. Collector and enthusiast he is working on his dream of manufacturing a caliber of its own craft.
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