The Rolex 5513/5517 Military Submariner dive watch had an estimated value of £80,000 to £120,000.
Starting at a £60,000 bid, it sold for well over its expected price in about two minutes at the online Bonhams auction on Wednesday.
A Perthshire resident took it to Crieff-based antique dealer Nick Brewster who said there was something special about it.
Speaking after the auction, Mr Brewster, of Nick Brewster Art and Antiques, said: “The hammer price of £155,000 plus commission was above what we had hoped for and both myself and my client are overjoyed with the result.
“It was a pleasure to be able to bring the watch to market and for it to achieve such a high price.”
He previously described the item as “one of the rarest and one of the most collectable watches today”.
Known as a MilSub, the watch was issued to a former Royal Navy diver in the 1970s by the Ministry of Defence and was bought from him by the second 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.
It is thought that between 1971 and 1979, only 1,200 of these watches were issued as standard basic equipment by the MoD, mainly for use by Navy submariners and their leading divers and mine-clearance personnel.
Auctioneers said the 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.