BOSTON - Rescue teams expanded their search underwater on Tuesday as they raced against time to find a deep-diving tourist submersible that went missing near the wreck of the Titanic with five people on board and limited oxygen.
All communication was lost with the 6.5m-long Titan craft during a descent Sunday to the Titanic, which sits at a depth of crushing pressure more than four kilometres below the surface of the North Atlantic.
The submersible was carrying three fee-paying passengers – British billionaire Hamish Harding, and Pakistani tycoon Shahzada Dawood and his son Suleman who are members of one of Pakistan's richest families.
Shahzada is the vice chairman of the subsidiary company Engro, which has an array of investments in energy, agriculture, petrochemicals and telecommunications.
Harding, a 58-year-old aviator, space tourist and chairman of Action Aviation, is no stranger to daredevil antics and has three Guinness world records to his name.
The US and Canadian Coast Guards have sent ships and planes in an intensive search for the vessel, which is equipped with just four days of oxygen.
Rear Admiral John Mauger, leading the search, told ABC News that rescuers had scoured an area of about 13 000 square kilometres.
Mauger said a P-3 plane from Canada has dropped sonar buoys in the area of the Titanic wreckage to listen for any sound from the small sub.
He added that the search, initially restricted to the ocean's surface, is now going under water as well.
France's oceanographic institute said it was sending a deep-sea underwater robot to aid efforts.
In an Instagram message posted just before the dive, Harding said a mission window had opened after days of bad weather.
Veteran Titanic expert
Among the crew he named was Paul-Henry Nargeolet, a veteran diver and expert on the Titanic wreck.
Nargeolet, 77, is a French submarine operator and daredevil deep-sea explorer dubbed "Mr Titanic".
Nargeolet has dived all over the world and spoke openly about the risks of his exploits in the most inaccessible waters of the world's oceans, often thousands of metres below sea level.
Nargeolet told the Irish Examiner newspaper in 2019:
"When you're in very deep water, you're dead before you realise that something is happening, so it's just not a problem,"
Nargeolet's family confirmed to the BFM TV channel that he was among the crew, which also included British businessman Hamish Harding and prominent Pakistani businessman Shahzada Dawood and his son.
Connecticut-based Nargeolet had already undertaken more than 30 dives to explore the Titanic and had supervised the recovery of around 5 500 objects, including a fragment weighing 20 tons that is displayed in Los Angeles.
After the discovery of the wreck in 1985, the mythical ship became the focus of the second half of his life after his retirement from a 25-year career in the French navy.
His research, written up in a 2022 book called In the Depths of the Titanic, also saw him question the findings of British and American enquiries into the disaster which concluded that the ship suffered a 100m-long gash in its side after hitting an iceberg.
Based on his observations and scans at the scene, he argued that five much smaller holes were to blame.
His work recovering objects from the ship on behalf of the US-based owner of the wreck, RMS Titanic, was the subject of criticism by relatives of the 1 500 people who perished on the ship, however.
Some of them felt the wreck should be left alone as a burial site and objected to a private company profiting from the tragedy, having been given the salvage rights under long-standing US maritime law.
In 2011, 5 000 artefacts found around the wreck were auctioned off including jewellery, a compass and megaphones, valued at $189 million.
Nargeolet argued that the sales were needed to fund more dives, and that they helped preserve the memory of those on board.
No human remains have been found around the site and any bodies which went down with the ship would have been dissolved in the acidic sediment on the sea floor.
Nargeolet was also a technical adviser in the so-called "Five Deeps Expedition" in 2019 with American explorer and private equity investor Victor Vescovo, which aimed to explore the deepest points in each of the world's five oceans.
Vescovo's 4.6m- long submersible called the DSV Limiting Factor set a record for the deepest dive after descending 11km in the Pacific Ocean's Mariana Trench.
In his interview with Le Monde last year, Nargeolet said one of his future plans was to study the sea creatures that had made the rusting hull of Titanic their home.
"The Titanic is an oasis in an immense desert," he said.
Tourist dives
Unconfirmed reports said the fifth person on board was Stockton Rush, the CEO of OceanGate Expeditions which operates the tourist dives.
OceanGate Expeditions charges $250 000 for a seat on the Titan.
The Titan lost contact with the surface less than two hours into its descent, according to authorities.
"We are exploring and mobilising all options to bring the crew back safely. Our entire focus is on the crew members in the submersible and their families," OceanGate said in a statement.
Mike Reiss, an American television writer who visited the Titanic wreck on the same sub last year, told the BBC the experience was disorientating. The pressure at that depth as measured in atmospheres is 400 times what it is at sea level.
"The compass immediately stopped working and was just spinning around and so we had to flail around blindly at the bottom of the ocean, knowing the Titanic was somewhere there," Reiss said.
He told the BBC that everyone was aware of the dangers.
"You sign a waiver before you get on and it mentions death three different times on page one.
"This isn't a coach holiday or something. Things go wrong."
A year ago, Reiss became a space tourist through Amazon founder Jeff Bezos's Blue Origin company.
Scenarios
The Titanic hit an iceberg and sank in 1912 during its maiden voyage from England to New York with 2 224 passengers and crew on board. More than 1 500 people died.
The wreckage is in two main pieces 644km off the coast of Newfoundland, Canada.
It was found in 1985 and remains a lure for nautical experts and underwater tourists.
Without having studied the craft itself, Alistair Greig, professor of marine engineering at University College London, suggested two possible scenarios based on images of the Titan published by the press.
He said if it had an electrical or communications problem, it could have surfaced and remained floating, "waiting to be found" – bearing in mind the vessel can reportedly be unlocked from the outside only.
"Another scenario is the pressure hull was compromised – a leak," he said in a statement. "Then the prognosis is not good."
There are very few vessels able to go to the depth to which the Titan might have travelled.
"The clock is ticking, and any submariner/submersible deep divers know how unforgiving the Abyssal domain is: going undersea is as, if not more, challenging than going into space from an engineering perspective," said University of Adelaide associate professor Eric Fusil in a statement.
Agence France-Presse (AFP)