A search is under way after a submersible that takes tourists to view the wreck of the Titanic went missing in the Atlantic Ocean.

Government agencies, US and Canadian navies and commercial deep-sea firms have joined efforts to find the vessel belonging to tour firm OceanGate.

The luxury tour company that promises unforgettable expeditions to see the wreckage of the Titanic has confirmed one of its submersibles has gone missing.

“We are exploring and mobilising all options to bring the crew back safely,” OceanGate said in a statement.

Who are Ocean Gate and how much does it cost?

OceanGate is a Washington-based company that has been offering trips to the wreck for several years, with six guests per voyage paying $250,000 (£195,000) for the privilege. This includes a guided tour around the famous ship 13,000ft beneath the sea, as well as luxury hospitality aboard an expedition vessel.

“You will arrive at depth, and after some navigating across the seafloor and debris field, finally see what you’ve been waiting for: the RMS Titanic,” says the company in its brochure.

“The content expert on board will point out key features, be they of the wreck itself or the life that calls this corner of the ocean home. Enjoy hours of exploring the wreck and debris field before making the two-hour ascent to the surface.”

The eight-day 2023 expedition was listed as “underway” on a cached page of the OceanGate website, with the original no longer online. The company did not answer calls to its office.

It is extremely exclusive, with the company saying it offers “a select number of individuals to explore the vessel that was once the height of opulence, but whose journey would end tragically”. It says it is a “once in a lifetime opportunity” to travel in the world’s only carbon-fibre submersible capable of diving five people.

OceanGate founder, businessman Stockton Rush, founded the company in 2009 promising to make the depths of the oceans accessible.

The former aerospace engineer told CBS News last year that the Titanic trips represent “a new type of travel”, blending adventure, luxury and history.

The famous wreck holds a powerful allure that draws passionate guests, he said.

“We have clients that are Titanic enthusiasts, which we refer to as Titaniacs,” Mr Rush added. “We’ve had people who have mortgaged their home to come and do the trip. And we have people who don’t think twice about a trip of this cost. We had one gentleman who had won the lottery.”

The expeditions also double as research opportunities for scientists, allowing them to study rare species in the depths of the Atlantic Ocean.

Visitors are warned that the experience can be unpredictable, with weather conditions interfering with previous expeditions.

OceanGate is one of several companies offering trips to the Titanic, located around 370 miles off the Canadian coast, with demand said to be intense. Scientists had previously warned that the number of visits from filmmakers and explorers was damaging the wreck.

Tourist visits to the Titanic have been controversial, with some relatives of victims of the 1912 disaster saying they are disrespectful to the dead.

What happened?

The sub normally communicates with its pilot ship the Polar Prince every 15 minutes but contact was lost about an hour and 45 minutes into the dive, the US Coast Guard said.

“We are deeply thankful for the extensive assistance we have received from several government agencies and deep sea companies in our efforts to re-establish contact with the submersible,” OceanGate said in a statement.

“We are working toward the safe return of the crew members.”

Rear Adm John Mauger of the US Coast Guard told a press conference they are doing “everything” they can to find the submersible.

“Right now, our focus is getting on as much capability into the area as we can,” he said on Monday, adding: “We anticipate that there’s somewhere between 70 to the full 96 hours at this point.

“It is a remote area and a challenge, but we are deploying all available assets.”

The US Coast Guard said the Canadian research vessel Polar Prince and 106 Rescue wing will continue to conduct surface searches while the US Coast Guard sent two C-130 flights to search for the missing submersible.

Who was on board the sub?

Five people were onboard the vessel, including one pilot and two “mission specialists”.

Pakistani businessman Shahzada Dawood and his son Suleman Dawood have been named as two of the other people on the submersible in a family 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.

Among the crew is British businessman and explorer Hamish Harding, chairman of private plane firm Action Aviation.

In a subsequently deleted Facebook post, Mr Harding’s stepson wrote that he had “gone missing on a submarine” and asked for “thoughts and prayers”.

The last pictures from before the dive were shared on Action Aviation’s Instagram account, depicting the submersible setting off into the depths.

Mark Butler, managing director of Action Aviation, said: “There is still plenty of time to facilitate a rescue mission, there is equipment on board for survival in this event. We’re all hoping and praying he comes back safe and sound.”

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

His cousin, Kathleen Cosnett, told The Daily Telegraph she saw Mr Harding as “daring” and “inquisitive”, and that she was “devastated” to learn he was missing.

On social media at the weekend, he said he was “proud to finally announce” he would be aboard the mission to the wreck of the Titanic, the luxury ocean liner which hit an iceberg and sank in 1912, killing more than 1,500 people.

The Explorer’s Club, of which Mr Harding is a founding member of, shared the news of his disappearance on Instagram with club president Richard Garriot saying: “When I saw Hamish last week… his excitement about this expedition was palpable,” he said.

“I know he was looking forward to conducting research at the site. We all join in the fervent hope that the submersible is located as quickly as possible and the crew is safe.”

Where is the wreckage of the Titanic?

The shipwreck of the Titanic is 3,800 metres down on the bed of the Atlantic Ocean, roughly 600km (370 miles) off the coast of Newfoundland, Canada.

The passenger liner hit an iceberg on its maiden voyage from Southampton to New York in 1912, with more than 1,500 of the 2,200 passengers and crew onboard dying.

The wreckage was discovered in 1985.