Welcome to Watches You Should Know, a biweekly column highlighting important or little-known watches with interesting backstories and unexpected influence. This week: the Rolex Military Submariner.
If the Rolex Submariner is the most famous dive watch, then the Rolex Military Submariner, or MilSub, is the most famous military-issued dive watch. What is now a highly sought after piece of watch history — and one of the rarest collector’s watches ever — was once merely Ministry of Defense (MOD) standard issue equipment.
The Brits were one of the early militaries to use divers for offensive purposes during wartime, complementing ongoing recon and defensive missions. Coming out of WWII, the MOD realized a robust and reliable dive watch would be absolutely necessary for diving units. At the time, Rolex was the clear leader in waterproof watch technology, catching the attention of the MOD and marking the first appearance of a military-issued Submariner.
Around 1957, when the MOD was ready to commit to the Submariner, Rolex was several years and several upgraded references into the Submariner’s history. The 6538, which would become known as the Bond Submariner for its time on Sean Connery’s wrist, was made into a MOD-spec version, the A/6538.

According to Mike Wood, one of the world’s preeminent collectors and authorities on MilSubs, the MOD required certain features that would differentiate the civilian and military Subs: fixed bars, requiring a nylon strap and ensuring the watch case isn’t leaving your person without an arm attached to it; a larger bezel, allowing gloved divers more gripping power; and a bezel material of German silver (a copper alloy not containing silver), which would typically dent upon impact, versus cracking or breaking.