Seiko Mods for Military Buffs: Build a Watch with Tool Watch Vibes

The Seiko modding community is in love with dive watches, and by extension, MilSpec watches. They both look great despite having relatively simpler designs, they’re functional, and they’re both built to weather harsh conditions, making them the perfect choice for many situations. If you’re a military buff and looking to build your custom watch that’s tailored for your preferences, then keep reading because this article is for you!

 

Source: Analog:Shift

 

In this article, we’re looking at a couple of great examples from history that you can use for inspiration on a future build, as well as looking at basic principles for choosing the parts for your watch. Get ready to channel your inner watchmaker and assemble a timepiece that’s as tough and stylish as the military watches that inspired it.

Inspirational Military Watches

Military-inspired tool watches serve its wearer beyond telling time while staying unassuming and blending with the rest of the uniform. They’re designed to be indispensable in demanding environments, featuring heavy duty cases, bold markers for easy readability, and a no-frills aesthetic. With a premise like that, there’s no wonder why they appeal to the more practical watch enthusiasts.

Before we go to picking the parts for your build, let’s dive into four legendary models that have shaped the military watch landscape: the Dirty Dozen, Benrus Type I/II, British MoD W10, and the Blancpain Fifty Fathoms.

Dirty Dozen, 1944–1945

Source: Mr Jones Watches

 

The Dirty Dozen refers to twelve Swiss watchmakers commissioned by the British Ministry of Defence (MoD) during World War II. These “WWW” (Watch, Wrist, Waterproof) models were the first non-civilian wristwatches issued to British forces. Key features include black dials with Arabic numerals, small seconds at 6 o’clock, luminous hands and markers (originally radium), and hand-wound 15-jewel movements regulated to high accuracy. The steel cases often featured fixed bars and Broad Arrow engravings on the caseback, alongside military issue numbers. Post-war, many were re-lumed with tritium, and parts were frequently swapped during service, making “matching numbers” rare. 

These 12 brands together make for a sought-after collection, probably the most coveted among MilSpec watches there is. Learn more about them in this article.

British MoD W10 (1970s)

Source: Antique Watch Co

 

The W10 was another standard-issue watch for the British Army but was made during the 1970s, with similar models going to the Royal Air Force (6BB) and Royal Navy (0552). These watches were first made by Hamilton and later by CWC, all following strict military standards.

The case was stainless steel, about 35 - 36mm wide, with a simple matte finish and fixed bars for extra durability. The black dial used easy-to-read Arabic numerals and sword-style hands. Inside, a hand-wound ETA 2750 movement kept time and included a hacking feature so the seconds hand could stop for precise setting - something important when coordinating very time-sensitive operations. On the dial, the Broad Arrow symbol and a circled “T” showed that tritium was used for the lume while the caseback featured engravings listing military codes, service branch, and year of issue. 

Benrus Type I and Type II (1972–1980)

Source: Wind Vintage

 

Built for U.S. Navy divers, SEALs, and other special forces, the Benrus Type I and II are classic American military dive watches. Their sturdy stainless steel cases had fixed bars and matte finishes to avoid glare which could be distracting during a mission. A rotating bezel with a 12-hour scale, along with an automatic movement that could hack, made them highly practical for standard issue watches.

The Type I had a very clean “sterile” dial with only shapes for markers, while the Type II added 12- and 24-hour markings for more versatility. Both were water-resistant to around 1,000 - 1,200 feet or roughly 300 - 350 meters. Like most MilSpec watches, the casebacks carried military codes, serial numbers, and contract details, while some rare “sterile” versions left off these markings for secret operations. Today, collectors need to watch out for fakes or altered parts, like modern bezels, polished cases, or newer movements being sold as originals.

Blancpain Fifty Fathoms and Tornek-Rayville TR-900 (1953–1960s)

The Blancpain Fifty Fathoms, developed in 1953 for French combat divers, is often regarded as the first true dive watch. It pioneered rotating timing bezel, luminous markers, and robust water resistance which set the standard for modern dive watches. Aside from the French military, the watch was also adopted by various military forces, including the German Bundesmarine and U.S. Navy, showing just how well it functioned in different settings.

Source: European Watch

 

Due to “Buy American” policies, the U.S. Navy used the Tornek-Rayville TR-900, a rebranded Fifty Fathoms. Approximately 1,000 units were produced, featuring a moisture ingress indicator, tritium lume, and MilSpec compliance. Most were destroyed after service though, making surviving examples extremely rare and a boon for collectors. 

Learn more about the Fifty Fathoms in this article.

Choosing the Right Base Watch

The first step in building your military-inspired Seiko mod is selecting the right base watch. The Seiko SKX007 is a classic choice. It’s a well-loved case design with a dive watch heritage so it already has that ‘functionality-first’ look. You can keep the bezel insert and just update the hands and dial with something more MilSpec-inspired like the Pioneer Pilot or Milspec Type 1.

For those who prefer a minimalist field watch vibe, the Seiko SNK809 is a fantastic option, with its clean dial and compact size. It’s a favorite base watch for modders who want to build a Hamilton Khaki Field homage, which is quite easy to achieve because all you have to do is swap in this dial along with your choice of hands and a matching NATO strap and you’re good to go. 

 

If you’d rather go the ‘build from scratch’ route though, we have a couple of great cases to start with. Our NMK931 for example, is a spitting image of the Dirty Dozen cases featuring a sleek case design with a minimalist pilot bezel with a flat top, as well as a proportional crown already bundled in. Just pair it with any dial with large hour markers and lumed hands and you’re pretty much set!

 

 

Any dive watch case is a good contender for a MilSpec build as long as you choose the right dial and hands, and maybe a function via the bezel insert. But recently, we have released the Fifty Fathoms-inspired case which has an actual history of being a military watch which makes it perfect for MilSpec Seiko mods. It has matching inserts, hands and dials, including a NoRad-inspired one so you can create a true-to-the-original tribute.

Looking for something a bit more unique? Check out the Type I and II MilSpec cases which feature the same Benrus-coded crown guard that extends to the lugs, or our Tonneau (barrel) shaped case that has a case shape for wearable comfort, or perhaps a pilot case with an aged steel finish to give it an antique impression. You can check out these cases and their compatible parts here.

Wrap Up

Military-inspired tool watches have a timeless appeal, and with Seiko mods, you can create a custom timepiece that’s uniquely yours. From selecting the right base watch to choosing the perfect parts, the process of building a military mod is as rewarding as the final product itself. 

Ready to start your own military-inspired Seiko mod? Explore our extensive collection of modding parts and tools to bring your vision to life. 

Happy modding!