Tributes have been paid to the five people lost onboard the Titan submersible by the president of the Explorers Club.
Richard Garriott de Cayeux said club members Hamish Harding and Paul-Henri Nargeolet were both “drawn to explore”.
He added that OceanGate Expeditions chief executive Stockton Rush was a friend of The Explorers Club and conducted lectures at its headquarters, and that Shahzada Dawood and his son Suleman’s “desire to explore as a family would have led them to our doorstep at some point in their futures”.
Mark Hannaford, a fellow member of the Explorers Club, also paid tribute to Mr Harding, saying he was a “good father” and someone who “pushed boundaries”.
Mr Hannaford also shared a text which Mr Harding sent to him before the dive began, it said: “Diving to Titanic later today! If weather holds.”
In a statement posted on Twitter, Mr Garriott de Cayeux said: “Dear fellow explorers, our hearts are broken. I am so sorry to have to share this tragic news.
“Our friends and fellow Explorers Club members Hamish Harding and Paul-Henri Nargeolet are lost, along with Stockton Rush, Shahzada Dawood and his son Suleman, while trying to reach the RMS Titanic.
“After deploying all the military and commercial resources available to search for the submersible, the US Coast Guard announced that remotely operated vehicles (ROVs) has announced the catastrophic implosion of the Titan submersible within the water column above the Titanic.
“We are thankful for the leadership from the US Coast Guard, US Navy, US Air Force, The White House, Members of Congress, Magellan Deep Water Specialists, partners, and collaborators who deployed as part of the search and rescue mission.
“We are also grateful for all our members and the scientific and exploration community around the world who have mobilised personnel and resources to support the search and rescue.
“Hamish Harding is a dear friend to me personally and to The Explorers Club. He holds several world records and has continued to push dragons off maps both in person and through supporting expeditions and worthy causes.
“Paul-Henri was elected to the club in 2001 and was one of the foremost experts on submersible expeditions to the Titanic.
“They were both drawn to explore, like so many of us, and did so in the name of meaningful science for the betterment of mankind.
“They pushed themselves in their entrepreneurial pursuits as they did in exploration.
“Stockton Rush was a friend of The Explorers Club and conducted lectures at our headquarters.
“While we did not know Shahzada Dawood and his son Suleman personally, their desire to explore as a family would have led them to our doorstep at some point in their futures, where we would have welcomed them.
“We’re heartbroken for the families, friends and colleagues of those who were lost. Their memories will be a blessing and will continue to inspire us in the name of science and exploration.
“With our deepest condolences, Richard Garriott de Cayeux, president, The Explorers Club.”
Mr Hannaford, 58, who is also CEO of World Extreme Medicine, said: “As Explorers we are typically an optimistic bunch and whilst there was a slim hope of survival we strove to recover and save Hamish and his fellow travellers.
“But fate has not allowed that.
“Somebody asked me how I feel that Hamish would want to be remembered.
“One thing I noticed very clearly was that he had a close relationship with his boys, and to be remembered as a good father, closely followed by somebody who pushed boundaries and encourage others to do the same.
“The families will be devastated as will the rescue teams.”
Originally from Devon, Mr Hannaford now resides in Dubai, saying it is “not far from where Hamish lived”.
