Rolex wristwatch issued to the Royal Navy and used by a diver is coming up for sale.

A Rolex military watch that has seen better days will be sold at auction tomorrow in London, according to a listing on the website of the auction house Bonhams.

Although missing its bezel, the unique Rolex Military Submariner «MilSub», is expected to fetch the current owner, a professional diver, between £80,000 and £120,000 ($97,600 to $146,00), according to Bonhams.

More Robust

The watches were commissioned by the Royal Navy in the 1970s and had enhancements that made them more robust than those sold commercially. For one, the hands were changed to so-called «sword hands» to make them more legible. Also setting it apart is a «T» on the dial signifying it is illuminated with tritium, the radioactive isotope of hydrogen.

Because of its more solid nature, the strap also differs from the conventional Rolex, with all MilSub versions using a NATO strap. The reverse of the watch has the serial number on the inside with the number given by the Ministry of Defense on the outside, which in the case of this watch, indicate it was issued in 1977.

Tool Watches

Such military issue watches are known as tool watches, suffering heavy damage during their service and often repaired.

The one coming up for sale was purchased from the original owner, a navy diver, in the early 1980s. Its current owner is a professional diver who lost the bezel whilst diving in the 1990s, according to Bonhams.