The family of a British billionaire have described him as "one of a kind" after the US Coast Guard said he and four others had been lost aboard the submersible Titan following a "catastrophic implosion".
Hamish Harding was on board the vessel headed towards the Titanic shipwreck along with four others - Stockton Rush, Shahzada Dawood and his son Suleman Dawood and Paul-Henri Nargeolet.
The Titan submersible lost contact with its mother ship Polar Prince an hour and 45 minutes into its journey about 435 miles south of St John’s, Newfoundland.
Mr Harding, 58, was chairman of private plane firm Action Aviation and father-of-two, as well as a seasoned explorer who held three Guinness World Records, including the longest duration at full ocean depth by a crewed vessel.
He dived to the lowest depth of the Mariana Trench in March 2021.
In a statement released by Action Aviation, the family said: "Today we are united in grief with the other families who have also lost their loved ones.
"Hamish Harding was a loving husband to his wife and a dedicated father to his two sons, whom he loved deeply. To his team in Action Aviation, he was a guide, an inspiration, a support, and a living legend.
"He was one of a kind and we adored him. He was a passionate explorer - whatever the terrain - who lived his life for his family, his business and for the next adventure. What he achieved in his lifetime was truly remarkable and if we can take any small consolation from this tragedy, it's that we lost him doing what he loved.
"He will leave a gap in our lives that can never be filled. We know that Hamish would have been immensely proud to see how nations, experts, industry colleagues and friends came together for the search and we extend our heartfelt thanks for all their efforts.
"On behalf of the Harding family and Action Aviation, we would like to politely request privacy at this incredibly difficult time."
The Titan submersible was estimated to have about a four-day supply of breathable air when it launched Sunday morning in the North Atlantic but experts repeatedly emphasised it was an estimate.
In a press conference on Thursday, the US Coast Guard confirmed all five were dead during the tragedy after debris was discovered on the ocean floor today.
"The debris is consistent with the catastrophic loss of the pressure chamber," Rear Adm. John Mauger, the First Coast Guard District, said Thursday. "Our most heartfelt condolences go out to the loved ones of the crew."
The debris found includes part of the pressure chamber, the nose cone, the front-end bell and the aft-end bell, a press conference held in Boston on Thursday was told.
A remotely operated vehicle (ROV) found debris fields on the North Atlantic Ocean sea floor around 1,600ft from the bow of the Titanic on Thursday morning.
Rear Admiral John Mauger, of the US Coast Guard, said the debris is "consistent with a catastrophic implosion of the vessel".
"This is an incredibly complex operating environment on the sea floor over two miles beneath the surface," he added.
Undersea expert Paul Hankin said: "We found five different major pieces of debris that told us that it was the remains of the Titan. "The initial thing we found was the nose cone which was outside of the pressure hull. We then found a large debris field.
"Within that large debris field we found the front-end bell of the pressure hull. That was the first indication that there was a catastrophic event. Shortly thereafter we found a second smaller debris field. Within that debris field we found the other end of the pressure hull - the aft end bell - which basically comprises the totality of that pressure vessel.
"We continue to map out the debris field, and as the admiral said, we will do the best we can to fully map out what's down there."
