The man, featured this week in PBS's popular show “Antiques Roadshow,” showed his virtually unworn 1971 Rolex Oyster Cosmograph to appraiser Peter Planes.
The veteran, who has not been identified, explained he was stationed in southeast Asia in the 1970s when he became fascinated by Rolex watches after seeing airline pilots of the era commonly wear them.
He said he enjoyed scuba diving at the time and believed this Rolex model would stand up well to water. He ordered it in November 1974 through the military base exchange and received it in April 1975.
"I found this particular watch where I could afford it, and I never used it. I looked at it and I said, `You know, this is really too nice to take down in salty water,' " he said. "I just kept it."
Not only did he keep the watch in a safe deposit box, the vet also held on to all purchase and maintenance documents, adding to its value, according to Planes.
When Planes told him the watch could be worth $400,000 at auction, the man collapsed in disbelief during the taping in Fargo, North Dakota.
"You OK?" Planes said calmly as the man went down heels over head. "Don't fall. I'm not done."
The man got up, grinning ear to ear, to get even more incredible news.
"Because of the condition of it, basically, it's a new old stock watch, no wear on it," Planes said. "We have all this complete documentation here, also, maybe one of the very few in the whole world that still was never worn, your watch, at auction, today, $500,000 to $700,000."
The amazed man said: "You got to be (expletive) me."
This model of Rolex is particularly beloved by collectors because Paul Newman wore it in his 1969 movie "Winning," according to Planes.