The former US Navy officer who first discovered the wreck of Titanic has described how the mission was originally a ruse to fool the Soviet Union.
Dr Robert Ballard said he was searching for a US nuclear submarine that had disappeared in 1968 in the north Atlantic, but did not want his country's Cold War enemies to follow him.
So instead in 1985 he told the world he was seeking the wreck of the Titanic, which at that stage many had tried and failed to find.
Dr Ballard recounted the tale during a visit to Northern Ireland to back a campaign to see 5,500 artefacts from the wreck brought to Belfast, and also prevent any more items being removed from the site.
Backers for the $20m (€17m) plan include James Cameron, the Hollywood director behind the Oscar-winning movie.
Dr Ballard recounted how during the Cold War, a submarine called the Scorpion "had vanished; we had no idea what happened to it, so we had to track it down. I was serving in the US Navy as a naval intelligence officer.
"I was asked by my commanding officer to map the Scorpion, find its weapons and see what its nuclear reactor was doing to the environment, but only we knew where it was and we didn't want the Soviets to follow us, so I needed a cover.
"So I told the world I was going after the Titanic when in fact I headed straight for the Scorpion.
"But I learned from finding the Scorpion how to find the Titanic - the debris field, how it had blown up on its way down, how the currents had carried it - and so I used that same technique to go after the Titanic."
He is particularly keen to protect the wreck site, describing how visiting it feels like a battle site.
"For me, it's like going to Pearl Harbour. As a naval officer, that is a very special place, or to Gettysburg where our country fought itself.
"That's very hallowed ground, so you don't go to Gettysburg with a shovel, and you don't take belt buckles off the Arizona at Pearl Harbour.
"Titanic deserves the same respect."
Dr Ballard has never viewed the artefacts from the wreck site, but says he will if they come to Belfast.
Meanwhile, Cameron said he strongly opposes cutting off and resurfacing sections of the world famous ship.
He said it would cost billions to raise the wreck itself. "The feasibility is pretty much zero unless one were to throw enough money at the problem to start a colony on Mars," he said.
"We're talking billions of dollars, it's a very daunting task working two miles under the surface of the ocean."