Just as 19th-century railroads pushed the development of the pocket watch to higher standards of performance, so the wars of the 20th century influenced the development of the wristwatch. A wide variety of watches were designed for and used by military aviators, divers, spies, and other personnel.
These military watches, from makers like Hamilton, Omega, Rolex, Breitling, Doxa, Fortis, Elgin, Gruen, Glycine, Zenith, and others, tended to be strong and rugged, with advanced features such as luminescent dials and extra navigation aids. In general, most military watches were what are known as hacks, which means that the second hands ticked forward in distinct increments instead of continuously, so that it was easier to synchronize watches.
During World War I, Omega made wristwatches for British Royal Flying Corps, as well as for communications troops in the U.S. Army. These military wristwatches had white enamel dials, Arabic numerals, radium skeleton hands, and either silver or chrome-plated metal cases. Some versions featured tempered-steel grids over the watch face to protect it from shocks.
Breitling was another favorite supplier to British forces. In 1923, Breitling developed the first chronograph with an independent pushpiece, making start and return-to-zero functions (known as flyback) simpler and more intuitive. The addition of a second return-to-zero pushpiece improved the wristwatch’s functionality for pilots, which is one of the reasons why the Royal Air Force made Breitling its official supplier in 1936.
Even during World War II, Breitling continued to innovate. In 1942, the company debuted its Chronomat, the first chronograph wristwatch to be fitted with a circular slide rule on the bezel. These watches proved popular with the non-military public after the war, and vintage Chronomats are highly collectible today.
Other World War II suppliers included Bulova, Elgin, and Waltham, all of whom produced the Type A-11 for the U.S. Army Air Force and the British RAF. Hamilton also made watches during World War II (more than 110,000 for the Army alone), but not the A-11. One of the rarest Hamilton watches from this period is the R88-W-800. Only about 15,000 were made—watches for the Navy had a black face, watches for the Marine Corps had a white face.
In addition to A-11s, Elgin made one of the most collectible vintage wristwatches of the World War II era, the Navy Canteen Military Dive Watch. These watches are distinctive because of their smaller face. This was not a style decision but a requirement to compensate for the extra-large size of the waterproof seal on the crown, which extended the overall width of the watch...
The Glycine Airman was one of many popular wristwatches from the Vietnam era, even though it was not the standard issue. One of its simplest (but most useful) features was the crown at 8 o’clock, which could be tightened down so that the 24-hour indicator on the bezel would not rotate accidentally. But perhaps the best thing about the watch from an airman’s point of view was the ability to stop the second hand so that watches could be synchronized precisely.
Even though the world was a relatively peaceful place during the 1970s, watch makers continued to supply military forces with their wares. One of the most collectible vintage military wristwatches from that decade is unquestionably the Rolex 5517 Submariner, which Rolex made for the British Royal Navy. It is believed that only about 1,200 of these watches were produced and that perhaps only a few hundred have survived. The "T" on the dial indicated the presence of a luminous isotope of hydrogen called tritium, which was used to illuminate the wristwatch’s sword-shaped hands. For serious watch collectors, a 5517 is often the centerpiece of a collection.