It's everyone's dream to stumble across a priceless heirloom and make their fortune. But very few are that lucky.
However, one man managed to do just that when he took an old watch of his onto the Antiques Roadshow, and he couldn't believe how much it was worth.
David served in the US Air Force during the Vietnam War, enlisting in the 1970s and working as an explosives ordnance disposal airman.
While out there, he told the show that he noticed a lot of airline pilots wore Rolex watches, but could never afford one himself.
Luckily, while he was doing a bit of diving, he came across a cheaper model, the 1971 Oyster Cosmograph, which he picked up for $345 – about a month's wage for him at the time – and which was supposed to be perfect for underwater pursuits.
However, when he actually got it, he couldn't bring himself to get it 'salty' and instead put it in a safety deposit box, where it stayed for 40 years.
David said: "I only took it out two or three times to look at it, and that was about the extent of it before I brought it here."
And it was probably wise keeping it safe all that time, because according to the expert, it is now worth an absolute fortune.
Explaining the significance of the model to David, the expert said: "These watches, as we've talked about on Antiques Roadshow, have become very collectable.
"It's got a couple of very special features about it. Underneath the word 'Rolex', and above the word 'Cosmograph', it says 'Oyster', and that refers to the screw down buttons here.
"It still has the foil sticker on the back, with the reference number 6263. Had it been worn, that would have been the first thing that would wear off the watch."
He also told David that Paul Newman wore a similar watch, minus the screw-down buttons, in the film Winning, which he says added to its value for collectors.
Now we come to the valuation.
The expert says: "The one that Paul Newman wore, currently at auction, those watches are going for approximately $100,000 to $200,000. Your watch is more special.
"It says 'Oyster' on it. They did that for an extremely short period of time – we refer to that as a Mark II dial. And this particular model being marked 'Oyster' is extremely, extremely rare. A watch like this, at auction, is worth around $400,000."
Bowled over by the valuation, David drops to the floor in utter disbelief.
But it's not over just yet. After getting back to his feet, the vet gets the real good news.
"I'm not done yet, I said a watch like yours," the expert goes on.
"Your watch, at auction today, [fetches] $500,000 to $700,000. It's an absolute fabulous find. It's one of the rarest Paul Newman models, and in this condition, I don't think there's a better one in the world."
But he rounded off by warning David: "You can't wear it, though. If you wear it, it drops down to the $400,000 value."