Vessel Vanishes on a Dive to Titanic Wreck, Setting Off a Search

The submersible vessel carrying five people slipped into the dark waters of the North Atlantic, heading to what remained of the Titanic, 12,500 feet under the sea. The expedition, like many before it, was a testament to the enduring fascination with the storied ship that struck an iceberg and sank off Newfoundland more than a century ago.

But one and a half hours into the dive on Sunday morning, the craft went missing, setting off a search by rescue crews from two countries and adding another layer of mystery and intrigue to the Titanic wreck.

Among those on board was Hamish Harding, a British aviation tycoon who took part in Blue Origin’s fifth human spaceflight last year and holds several Guinness World Records, including for the longest time spent traversing the deepest part of the ocean on a single dive.

In social media posts, Mr. Harding had written excitedly about the upcoming trip: “I am happy to finally announce that I joined @oceangateexped for their RMS TITANIC mission as a mission specialist on the sub going down to the Titanic,” he said on Instagram. “More expedition updates to follow,” he added, “IF the weather holds.”

On Monday, officials had no explanation for why the craft, called the Titan, lost contact with its Canadian expedition ship on the surface, MV Polar Prince, about 400 miles south of St. John’s, Newfoundland.

But a spokesman for the U.S. Coast Guard, Rear Admiral John Mauger, said at a news conference that the people on the vessel, which was designed to survive an emergency for 96 hours, would theoretically have at least 70 to 96 hours of oxygen before the situation became dire.

“We’re using that time making the best use of every moment of that time,” he said.

The Coast Guard was coordinating with the Canadian authorities and commercial vessels to help search an area approximately 900 miles east of Cape Cod, at a depth of roughly 13,000 feet, he said. Sonar buoys were deployed into the water, and the expedition ship was using sonar to try to locate the submersible. Aircraft from the United States and Canada, along with surface vessels, were scanning the waves in case the submersible had surfaced and lost communications, he said.

“We are doing everything we can do,” Admiral Mauger said at the news conference, adding that it was “a challenge to conduct a search in that remote area, but we are deploying all available assets to make sure that we can locate the craft and rescue the people on board.”

Officials have not released the names of those on the craft, but Mr. Harding, chairman of a Dubai-based sales and air operations company, Action Aviation, was confirmed as being on board the missing submersible by Mark Butler, managing director of the company.

The 21-foot craft is operated by a Washington State-based company, OceanGate Expeditions, which offers tours of shipwrecks and underwater canyons for $250,000 a person. In a statement on Monday, OceanGate said: “Our entire focus is on the crew members in the submersible and their families. We are deeply thankful for the extensive assistance we have received from several government agencies and deep sea companies in our efforts to reestablish contact with the submersible.”

The Marine Institute at the Memorial University of Newfoundland in Canada, which partnered with OceanGate on the trip, said in a statement that it became aware on Monday morning that OceanGate had lost contact with its Titan submersible. “We have no further information on the status of the submersible or personnel,” it said in a statement.

RMS Titanic, a luxury liner and the world’s largest ship when built, struck an iceberg and sank one Sunday in April 1912, on its maiden voyage from Southampton, England, to New York City. For decades afterward, searchers explored the North Atlantic for the ship’s wreck on the ocean floor.

Finally, in 1985, a team took undersea robots to depths of more than 12,000 feet and verified that the broken hulk it had found less than 400 miles from Newfoundland was, indeed, the Titanic of lore.

The deteriorating ruin of the Titanic lies in waters some two and a half miles deep — far deeper than ordinary submarines can venture. At that depth, the water pressure is hundreds of times as high as it is just below the surface.

A submersible traveling down to the Titanic faces soaring, crushing pressure during its long descent. At the ship’s resting place, the weight of the icy ocean pressing down would be equal to a tower of solid lead overhead rising to the height of the Empire State Building.

Typically, searchers and researchers looking in such inky depths rely on advanced robots that use remote-controlled television, photography and sonar-mapping systems that can survive the crushing pressures and pierce the darkness. But such exploratory work is expensive and often frustrating.

In 2014, Malaysia Airlines Flight 370 went missing in the Indian Ocean west of Australia, with 239 people aboard, and search parties looked in vain for its wreckage.

“It has been said that we know more about the surface of the moon than our own seabed,” Commodore Peter Leavy of the Royal Australian Navy, who helped lead the hunt for the missing jetliner, told reporters in Perth.

For 111 years, the Titanic shipwreck had garnered intense interest among researchers and treasure hunters captivated by its tragic history: the horror of the accident, the inadequacy of the lifeboats, the supposed hubris of the ship’s builders and operators, the enormous wealth of many and the poverty of others on board, and the deadly indifference of the iceberg and the sea.

Tourists were paying up to $36,000 per dive by submersible in the early 2000s. Salvage crews hunted for artifacts to bring back up, over the objections of preservationists who said the wreck should be honored as the graveyard of more than 1,500 people. Wreckage from a submersible accident was found on one of the Titanic’s decks. Researchers said the site was littered with beer and soda bottles and the remains of salvage efforts, including weights, chains and cargo nets.

James Cameron, the award-winning director, reinvigorated interest in the ship with his 1997 film, “Titanic. Mr. Cameron’s cinematic hit imbued the wreck with a new story of romance and tragedy, renewing interest far beyond those with an interest in famous maritime accidents.

By the early 2000s, scientists were warning that visitors were a threat to the wreck, saying that gaping holes had opened up in the decks, walls had crumpled, and that rusticles — icicle-shaped structures of rust — were spreading all over the ship.

Mr. Cameron, who has repeatedly visited the Titanic, was among those calling for care around the site. He took 3-D cameras there for his 2003 documentary, “Ghosts of the Abyss.”

By the time OceanGate Expeditions, a private company founded in 2009, began offering tours to paying customers, researchers said that the Titanic had little scientific value compared with other sites. But cultural interest in the ship remains extraordinarily high, and the disaster continues to command a fascination online, sometimes at the expense of facts.

Last summer, the president of OceanGate, Stockton Rush, told The New York Times that private exploration was needed to continue feeding public fascination with the wreck site.

“No public entity is going to fund going back to the Titanic,” Mr. Rush said. “There are other sites that are newer and probably of greater scientific value.”

OceanGate also shared a one-minute clip of video obtained during one of its trips to the wreck site. Mr. Rush said that the high quality of the footage allowed researchers to get an even closer look at the site without having to go underwater.

He compared the OceanGate trips to space tourism, saying the commercial voyages were the first step to expanding the use of the submersibles for industrial activities, such as inspecting and maintaining underwater oil rigs.

The dives offered by the company last about eight hours, including the estimated 2.5 hours each way it takes to descend and ascend. Scientists and historians provide context on the trip and some conduct research at the site, which has become a reef that is home to many organisms. The team also documents the wreckage with high-definition cameras to monitor its decay and capture it in detail.

In a post on his Facebook page on Saturday, Mr. Harding, who boarded the submersible before it lost contact, said of the planned dive: “A weather window has just opened up.”

In his Instagram post, he wrote, “The team on the sub has a couple of legendary explorers, some of which have done over 30 dives to the RMS Titanic since the 1980s.”

He also said, “Due to the worst winter in Newfoundland in 40 years, this mission is likely to be the first and only manned mission to the Titanic in 2023.”

Amanda Holpuch and William J. Broad contributed reporting.