Missing submersible on Titanic expedition: What we know so far

SINGAPORE: A search is underway for a deep-sea vessel that went missing with five people aboard after it dove toward the deteriorating wreck site of the Titanic ocean liner.

The United States Coast Guard is leading the search for the small craft, the Titan, in the North Atlantic Ocean.

The remote area is where the Titanic struck an iceberg and sank in 1912, killing all but about 700 of the roughly 2,200 passengers and crew.

The Titan's dive on Sunday (Jun 18) was one of many that have been made to the wreck by OceanGate Expeditions since 2021.

The US-based undersea exploration company has been chronicling the ship's decay as well as the underwater ecosystem that has sprung up around it over the last century.

Here is what we know about the situation so far.

What kind of vessel is missing?

The Titan is a 6.5m-long manned submersible that can carry five people – a pilot and four passengers – to depths of up to 4,000m, according to OceanGate's website.

Expeditions to the Titanic, which cost US$250,000 per person, start in St John's, in the Canadian province of Newfoundland and Labrador.

There, passengers board a support ship, the Polar Prince in this case, which heads out 640km into the Atlantic to the wreckage site.

To visit the wreck, passengers climb inside the Titan, which takes two hours to descend about 3,800m to the Titanic.

In a May 2021 court filing, OceanGate said that the Titan had an "unparalleled safety feature" that assesses the integrity of the hull throughout every dive.

At the time of the filing, the Titan had undergone more than 50 test dives, including to the equivalent depth of the Titanic, in deep waters off the Bahamas and in a pressure chamber, the company said.

During its 2022 expedition, OceanGate reported that the submersible had a battery issue on its first dive and had to be manually attached to its lifting platform, according to a November court filing.

According to the BBC, who spoke to a journalist who travelled on board the Titan last year, passengers are sealed inside the submersible by bolts that are applied from the outside.

Passengers are not able to exit the vessel without the help of crew members on the outside.

How did it go missing?

The Titan began its descent on Sunday morning but lost contact with the Polar Prince about one hour and 45 minutes later.

The US Coast Guard said the vessel can remain submerged for 96 hours and would have had about 70 hours or more of remaining oxygen as of Monday afternoon.

It is unclear whether the submersible was still underwater or if it had surfaced and was unable to communicate.

Who is on board?

British billionaire and adventurer Hamish Harding is among the passengers, according to a social media post from a relative.

Harding's stepson wrote on Facebook that Harding had "gone missing on (a) submarine" and asked for "thoughts and prayers". The stepson subsequently removed the post, citing respect for the family's privacy.

Harding himself had posted on Facebook that he would be aboard the sub. There have been no further posts from him.

The expedition headed out to sea on Friday, and the first dive was set for Sunday morning, according to Harding's post.

Action Aviation, a company for which Harding serves as chairman, also posted about his expedition.

Harding holds three Guinness World Records, including for the longest duration spent at full ocean depth by a crewed vessel.

In March 2021, he and ocean explorer Victor Vescovo dived to the lowest depth of the Mariana Trench. In June 2022, he went into space on Blue Origin's New Shepard rocket.

Pakistani businessman Shahzada Dawood and his son, Suleman, are also on board, their family said in a statement.

"We are very grateful for the concern being shown by our colleagues and friends and would like to request everyone to pray for their safety," the statement said.

Dawood is the vice-chairman of one of Pakistan's largest conglomerates, Engro Corporation, which has investments in fertilisers, vehicle manufacturing, energy and digital technologies.

According to the website of SETI, the California-based research institute of which he is a trustee, he lives in Britain with his wife and two children.

Paul-Henri Nargeolet, a 77-year-old French explorer, is another person reportedly on board. He is the director of underwater research at a company that owns the rights to the Titanic wreck.

A former commander in the French navy, he was both a deep diver and a minesweeper. After retiring from the navy, he led the first recovery expedition to the Titanic in 1987 and is a leading authority on the wreck site.

The fifth person reportedly on board is Stockton Rush, the founder and CEO of OceanGate.

"It is an amazingly beautiful wreck," Rush told Britain's Sky News of the Titanic earlier this year.

Rush became the youngest jet transport rated pilot in the world when he obtained his DC-8 Type/Captain's rating at the United Airlines Jet Training Institute in 1981 at the age of 19, according to his biography on OceanGate's website.

What might have happened?

Alistair Greig, a professor of marine engineering at University College London, said that submersibles typically have a drop weight, which is "a mass they can release in the case of an emergency to bring them up to the surface using buoyancy".

"If there was a power failure and/or communication failure, this might have happened, and the submersible would then be bobbing about on the surface waiting to be found," Greig said.

Another scenario is a leak in the pressure hull, in which case the prognosis is not good, he said.

How might it be recovered?

If the Titan has gone down to the seabed and cannot get back up under its own power, options are very limited, Greig said.

"While the submersible might still be intact, if it is beyond the continental shelf, there are very few vessels that can get that deep, and certainly not divers," he said.

Even if they can go that deep, he doubts they can attach to the hatch of OceanGate's submersible.

David Concannon, an adviser to OceanGate, told the Associated Press on Monday that officials are working to get a remotely operated vehicle that can reach a depth of 6,000m to the site as soon as possible.

What are the resources that have been deployed in the search effort?

US and Canadian ships and planes have swarmed the area, some dropping sonar buoys that can scan beneath the waves to depths of almost 4km, US Coast Guard Rear Admiral John Mauger told reporters on Monday.

"It is a remote area and it is a challenge to conduct a search in that remote area," Mauger said.

"We are deploying all available assets to make sure that we can locate the craft and rescue the people on board," he added.

"Going into this evening we will continue to fly aircraft and move additional vessels."

Mauger said that officials have also been reaching out to commercial vessels for help.

The US Coast Guard's Boston-based unit said in a tweet at around 9pm on Monday (1am GMT on Tuesday) that its flights for the day "have been completed" with no reported sightings of the vessel or communication signals.

The Polar Prince and a US Air National Guard unit are continuing to carry out surface searches overnight.

Searches by Canadian aircraft will continue on Tuesday morning.

On Tuesday, Mauger said that authorities were expanding their search into deeper waters.

"As we continue on with this search ... we've been working through the night with a broad group of partners to bring all capabilities to bear looking on both the surface and now expanding to a subsurface in the area," he told CNN in an interview.