Key events
Angelique Chrisafis
Among those believed to be on board the submarine is Paul-Henri Nargeolet, a 77-year-old former French navy commander known as “Mr Titanic”.
He has been studying the Titanic for 35 years and has been involved in several submarine expeditions to the wreckage and what have been described as hundreds of hours of observation.
In 1987 he was part of the team that brought up a series of objects from the wreckage. In an interview with Le Parisien last year, he described the first time he saw the wreck which lies in total darkness, covered with coral.
He said he glimpsed it from inside his submarine, detected with sonar and lit by projectors and said he and the team were left speechless. “For 10 minutes, there was no sound on the submarine.”
Nargeolet, who has been based in Connecticut in the US for many years, has described the wreckage as a “time capsule” where life suddenly stopped, endlessly fascinating to so many people for different reasons. “Some are interested in its construction, others in the history of immigration to the US, others are interested in the millionaires on board, the stars of the era.”
He told Le Monde last year of the vast number of species of marine life living around the wreck, saying: “The Titanic is an oasis in an immense desert.”
A writer who took the Titanic submersible trip last year said he is “not optimistic” over the search for the missing OceanGate craft.
Mike Reiss told BBC Breakfast communication was also lost during his dive down to the Titanic.
Reiss said: “I’m not optimistic just because I know the logistics of it. And I know how vast the ocean is, and how very tiny the craft is.
He added: “So the idea is, if it’s down at the bottom, I don’t know how anyone’s going to be able to access it, much less bring it back up.
“There is a hope that it’s at, or near, the surface.
“I did three separate dives. I did one dive to the Titanic and two more off the coast of New York.
“Every time they lost communication and again, this is not a shoddy ship or anything.”
The search is being led by the US Coastguard 1st District, which is based in Boston, Massachusetts, where it is currently 5.30am.
Who is the British billionaire explorer missing at sea?
Hamish Harding, 58, is one of the five missing with the OceanGate Expeditions vessel, which was reported overdue on Sunday evening about 435 miles south of St John’s, Newfoundland.
Harding is the chair of the private plane firm Action Aviation. His wife is called Linda, and he has two sons named Rory and Giles, as well as a stepdaughter named Lauren and a stepson, Brian Szasz.
As a student, he left Cambridge with a degree in natural sciences and chemical engineering.
Harding is an aviator, holding an airline transport pilot’s licence and business jet type ratings, including the Gulfstream G650. He is also a skydiver, was inducted into the Living Legends of Aviation in 2022, and is a trustee of the Explorers Club.
He also previously worked with the Antarctic VIP tourism company White Desert to introduce the first regular business jet service to Antarctica.
Harding has made many trips to the south pole and, in 2016, accompanied Buzz Aldrin, who became the oldest person to reach the south pole at 86. He also went into space last year with Jeff Bezos’ Blue Origin company.
Harding is the current holder of three Guinness world records, relating to his work as an adventurer. In 2019, he was commended for the fastest circumnavigation of the Earth via both poles.
As part of a crew of eight astronauts and aviators in a Qatar executive Gulfstream G650ER ultra-long-range business jet, Harding led the mission to mark the 50th anniversary of the Apollo 11 moon landing by Neil Armstrong and Buzz Aldrin. He achieved the feat in 46 hours, 40 minutes and 22 seconds.
In 2021, he achieved the greatest distance covered at full ocean depth and the greatest duration spent at full ocean depth.
Alongside Victor Vescovo, Harding dove in a two-man submarine to the lowest point in the world’s oceans, the deepest point of the Mariana Trench, the Challenger Deep – a depth of about 36,000ft.
Graham Russell
What can be done to find it?
US and Canadian aircraft are searching the area, as well as large ships, but the hunt was “complex” because crews do not know if the vessel has surfaced, meaning they must scour both the surface and the ocean depths, said Rear Admiral John Mauger, first district commander of the US Coast Guard, overseeing the search-and-rescue operation.
Concannon said officials were working to get a remotely operated vehicle (ROV) that can reach a depth of 6,000 metres (about 20,000ft) to the site as soon as possible.
These ROVs are dropped over the side of a vessel, to which it is connected by a “umbilical cord” that enables a pilot to operate its thrusters and also relay data in real-time from its sonar and camera systems.
However, the amount of wreckage of the Titanic on the ocean floor means it could take time to discern what is debris and what is the Titan. The search teams do at least have a starting point; the vessel’s position would have been tracked until the moment contact was lost.
The company’s managing director, Mark Butler, told the AP: “There is still plenty of time to facilitate a rescue mission, there is equipment on board for survival in this event,” Butler said. “We’re all hoping and praying he comes back safe and sound.”
Graham Russell
What might have gone wrong?
It is too early to say what has happened but experts have offered several of the most likely scenarios, from becoming tangled in wreckage of the Titanic, to a power failure or an issue with the sub’s communications system.
The wreckage of the Titanic, which lies about 3,800 metres (12,500ft) down on the ocean floor is surrounded by debris from the disaster more than a century ago.
“There are parts of it all over the place. It’s dangerous,” said Frank Owen OAM, a retired Royal Australian Navy official and submarine escape and rescue project director.
Contact was lost one hour 45 minutes into the Titan’s trip, suggesting the crew may have been close to, or at, the bottom, says Owen. The Titan has a maximum speed of three knots, but would be slower the deeper it goes.
In the case of becoming tangled, or a power or communications failure, the Titan would be equipped with drop weights, which can be released in an emergency, creating enough buoyancy to take it to the surface. The Titan has an array of signals, lighting, reflectors and other equipment it can use once on the surface to attract attention.
Another scenario is that there has been a leak in the pressure hull, in which case the prognosis is not good, said Alistair Greig, a professor of marine engineering at University College London.
“If it has gone down to the seabed and can’t 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.”
Chris Parry, a retired rear admiral with the British Royal Navy, told Sky News a seabed rescue was “a very difficult operation”.
“The actual nature of the seabed is very undulating. Titanic herself lies in a trench. There’s lots of debris around. So trying to differentiate with sonar in particular and trying to target the area you want to search in with another submersible is going to be very difficult indeed.”
Graham Russell
What is the Titan sub and what can it do?
The Titan is a research and survey submersible that can carry five people, usually a pilot and four “mission specialists” who can include archaeologists, marine biologists or anyone who can afford the experience as a tourist.
Made of “titanium and filament wound carbon fibre”, the 6.7-metre (22ft) craft weighs 10,432kg (23,000lbs), equivalent to about six average-size cars, and is capable of diving to depths of 4,000 metres (13,120ft) “with a comfortable safety margin”, according to operator OceanGate.
It uses four electric thrusters to move around, and has a battery of cameras, lights and scanners to explore its environment. OceanGate says Titan’s viewport is “the largest of any deep diving submersible” and that its technology provides an “unrivalled view” of the deep ocean.
It uses Elon Musk’s Starlink satellite technology to communicate, though it is unclear if it was the cause of the loss of contact. OceanGate tweeted last week: “Without any cell towers in the middle of the ocean, we are relying on @Starlink to provide the communications we require throughout this year’s 2023 Titanic expedition.”
It has a 96-hour bottled oxygen supply, as of roughly 6am Sunday local time, according to David Concannon, an adviser to trip operator OceanGate, which would in theory last until Thursday morning . However, that limit would be affected by the breathing rate of those inside the craft, especially if there are tourists onboard with limited diving experience.
Opening summary
Welcome to the Guardian’s live coverage of the search for the submersible vessel Titan that went missing during a voyage to the Titanic shipwreck.
Rescue teams are continuing the search for Titan which went missing with British billionaire Hamish Harding among the five people aboard.
Harding, is the chair of private plane firm Action Aviation, which said he is one of the mission specialists on the five-person OceanGate Expeditions vessel reported overdue on Sunday evening about 435 miles south of St John’s, Newfoundland.
Pakistani businessman Shahzada Dawood and his son Sulaiman Dawood have been named as two of the other people on the submersible in a family statement.
The other two passengers have been widely reported as being French explorer Paul-Henry Nargeolet and OceanGate chief executive and founder Stockton Rush.
It is understood there were 96 hours – four days – worth of oxygen supply on board which would have started on Sunday morning.
We’ll provide updates on the search when they are available.
