A submersible watercraft with five people on board has been missing since Sunday after setting out to explore the site of the Titanic shipwreck in the North Atlantic. The vessel is thought to be equipped with only a few days’ worth of oxygen.
An international team including the American and Canadian Coast Guards, commercial vessels, sonar buoys and aircraft have been involved in the search.
Here’s what we know.
When and where did the submersible disappear?
The 22-foot carbon-fiber and titanium craft called the Titan was deployed by a Canadian expedition ship, the MV Polar Prince, to travel nearly 13,000 feet down to the shipwreck site off Newfoundland.
The vessel lost contact with the surface ship one hour and 45 minutes after it started to dive on Sunday, the U.S. Coast Guard said.
Who owns the vessel, and why was it diving?
OceanGate Expeditions, a private company, operates the submersible. For this trip, it partnered with the Marine Institute at the Memorial University of Newfoundland in Canada.
OceanGate organizes expeditions that can last up to nine days for tourists willing to pay a hefty price to travel in submersibles to shipwrecks and underwater canyons. According to the company’s website, OceanGate also provides crewed submersibles for commercial projects and scientific research.
The company was founded by Stockton Rush, an aerospace engineer and pilot, who also serves as its chief executive officer.
OceanGate calls the Titan the only crewed submersible in the world that can take five people as deep as 4,000 meters — or more than 13,100 feet — enabling it to reach almost 50 percent of the world’s oceans. Images of the vessel show those onboard would have limited space to stand or sit.
Who was on board?
There are five people in the craft. As of Tuesday morning, three of them had been identified: Hamish Harding, a British businessman and explorer, and the Pakistani businessman Shahzada Dawood and his son, Suleman.
Mr. Harding is a veteran of other extreme deepwater dives and has flown to space on a mission organized by the Blue Origin rocket company. Mr. Dawood is part of one of Pakistan’s wealthiest families and vice chairman of Engro Corporation, a conglomerate that started out as a fertilizer business.
Where is the Titanic wreck, exactly?
Once the biggest steamship in the world, the Titanic hit an iceberg four days into its first voyage, in April 1912, and sank to the bottom of the Atlantic. More than 1,500 people died.
It was discovered in pieces in 1985, about 400 miles off Newfoundland.
Searchers are scouring the sea.
The Coast Guard was coordinating with the Canadian authorities and commercial vessels to help search. 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, said a spokesman for the U.S. Coast Guard.
But it’s a very difficult search.
A vessel traveling down to the Titanic faces 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.
For search-and-rescue operations at sea, weather conditions, the lack of light at night, the state of the sea and water temperature all play a role in whether stricken mariners can be found and rescued.
Rescuing people beneath the waves is even more difficult. Many underwater vehicles are fitted with an acoustic device that emits sounds that can be detected underwater by rescuers. It’s unclear if the Titan has one.
An additional hazard could be the vessel becoming hung up on a piece of wreckage, which could keep it from returning to the surface.
If the submersible is found at the bottom of the sea, the extreme depths would limit the possible means for a rescue. Divers wearing specialized equipment and breathing helium-rich air mixtures can safely reach depths of just a few hundred feet below the surface before having to spend long periods decompressing on the way back up. A couple hundred feet deeper, light from the sun will no longer penetrate the water.
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 can be expensive and frustrating.
“We are doing everything we can do,” said Rear Admiral John Mauger, spokesman for the U.S. Coast Guard.
Reporting was contributed by William J. Broad, Emma Bubola, Amanda Holpuch, John Ismay, Jesus Jiménez, Victoria Kim, Salman Masood and Alan Yuhas.