The anonymous Perthshire diving enthusiast took the government-issued Rolex 5513/5517 Military Submariner dive watch to Crieff-based antique dealer Nick Brewster, who said on “first sight of this exquisite watch, I felt that there was something about it”.
The watch, known as a MilSub, was issued to a former Royal Navy diver in the 1970s by the Ministry of Defence and was bought from him by the current owner in the early 1980s.
From then on the rare item became his go-to dive watch until the bezel fell off in a dive in 1996 and it was then stored in a chest of drawers.
But on Wednesday, the MilSub will go on sale at Bonhams, in London’s New Bond Street, with an estimated price of between £80,000 to £120,000.
Mr Brewster, of Nick Brewster Art and Antiques, said: “The market for exceptional watches is buoyant at the moment. The last original MilSub to reach the Bonhams London saleroom made £180,000, back in February.”
It is thought between 1971 and 1979, only 1,200 of the watches were issued as standard basic equipment by the MoD, mainly for use by Navy submariners and their leading divers and mine-clearance personnel.
Today it is estimated there are only 120 to 180 that still exist.
Mr Brewster said: “It is really fantastic when customers bring in their antiques and art for me to value and sell, even better when it is something so special.
“Although not a jewellery or watch dealer, on first sight of this exquisite watch, I felt that there was something about it that made it stand out.
“After a wee bit of research, I realised that it was an original Rolex MilSub, bar the missing bezel, one of the rarest and one of the most collectable watches today.”
Auctioneers said the Rolex Military Submariner’s unique military-designated features of tritium “T” on the dial, sword hands, 60-minute bezel, fixed lug bars, nylon strap, non-reflective case and military engravings to its back set the MilSub apart from any other Rolex Submariner watch.