The post-WWII “6B” watches are some of the finest three-hand military pieces ever made. The Omega 6B/542 is the perfect model for the collector looking for one of the more desirable 6Bs. Mid-century Omega movements were made to a very high standard, and the Ministry of Defense requirements ensured that Omega built a tough, durable watch capable of performing in adverse conditions.

Omega built these watches for only about a year according the guidelines issued by British Ministry of Defense, which covered everything from the movement to the dial and hands. The case could not have any highly polished parts, and the movement had to be protected from magnetic fields. The dial had to be black with white numerals, the hour and minute hands had to be skeletonized and filled with lume, and the seconds hand has to be white.

With such a detailed recipe, it’s easy to see why all of the 6Bs, whether made by JLC, IWC, Omega, Smiths, or Hamilton, looked so similar.

But the Omega “Fat Arrow” has an interesting bit of history regarding the dial that sets it apart from the other 6Bs: these watches were originally lumed with radium, but it proved to be so radioactive that in the 1960s the Ministry of Defense insisted that Omega recall the watches (similar to what the MOD decreed from ). Omega swapped the radium dials for tritium replacements, and printed a thicker white arrow to indicate the safer luminescent material--the source of the "Fat Arrow" nickname.

With its 36mm case, this 6B is a great size for modern wrists, and the RAF origins makes the watch a fantastic piece of military history. These watches have become wildly popular over the past few years and they’re harder to come by than ever.