A rare Rolex Submariner 5513 diver’s wristwatch from 1963, whose owner had a military history, hammered for £40,000 (about $50,000) at an English auction house last week after appearing on Antiques Roadshow on the BBC. 

The seller’s father, Simon F. L. Barnett, bought the watch for £70 (about £1,200 today, or $1,500) in Singapore while deployed as the ship’s diver aboard the aircraft carrier HMS Victorious, and wore it during his years as a search and rescue diver with the Royal Navy, according to the auction house TW Gaze in England. The timepiece sold at the higher end of its £30,000–£45,000 estimate.

His son, Pete Barnett, told the BBC that his father used the watch during his career in the navy to time his dives. “He had to know how long he had been under the water and that was the only means by which he could do it,” he said.

The Submariner, introduced in 1953 and the first watch engineered to be waterproof up to 100 meters, is widely considered one of the most important sports watches of all time. It had a rotating 60-minute bezel to help divers keep track of their time underwater, and was equipped with luminous material for readability at darker depths. Early scuba enthusiast (and Rolex board member) René-Paul Jeanneret conceived of the idea for the model.

Barnett was involved in numerous dramatic rescue and recovery missions. While serving aboard the HMS Hermes on the Mediterranean Sea in 1967, Barnett contributed to recovery missions after two fatal aircraft accidents. On one occasion, he nearly drowned and had to be pulled from the water, covered in fuel, after attempting to free a trapped helicopter pilot, but was quickly back on duty.

Backside of the watch. Courtesy of TW Gaze.

Barnett’s actions earned him a Commander-in-Chief’s commendation. After his time with the Royal Navy, he served with the Metropolitan Police until his retirement, and wore the same watch the rest of his life. Etched on the back are his name and that of his wife, Dawn.

Though the wristband on Barnett’s example was replaced around 1980, Barnett held on to the original, and the timepiece comes with its original green leather box and paperwork. It was serviced only twice and has never been polished.