What you need to know about the missing Titan submarine and the race to find it

A submarine with five people aboard has been missing since Sunday after it set out to investigate the site of the Titanic shipwreck in the North Atlantic. The ship is believed to be equipped with only a few days of oxygen.

An international team including the US and Canadian Coast Guards, commercial vessels, sonar buoys and aircraft is involved in the search.

Here’s what we know.

When and where did the submarine disappear?

Called the 22-foot carbon fiber and titanium craft the Titan was deployed by a Canadian expedition ship, the MV Polar Prince, to descend nearly 4,000 feet to the shipwreck site off the coast of Newfoundland.

The ship lost contact with the surface vessel an hour and 45 minutes after it began diving on Sunday, the US Coast Guard said.

Whose ship is it and why did it dive?

OceanGate Expeditions, a private company, operates the submarine. For this trip, it partnered with the Marine Institute at 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 websiteOceanGate also provides manned submersibles for commercial projects and scientific research.

The company was founded by Stockton Rush, an aerospace engineer and pilot, who also serves as CEO.

OceanGate calls the Titan the only manned submarine in the world that can take five people as deep as 4,000 meters — or more than 13,100 feet — allowing it to reach nearly 50 percent of the world’s oceans. Images from the ship show that those on board have limited space to stand or sit.

The company has been taking people on tours of the Titanic site since 2021, and guests have paid $250,000 to travel to the wreck.

Who was on board?

There are five people in the craft. By Tuesday morning, three of them had been identified: Hamish Harding, a British businessman and explorer, and Pakistani businessman Shahzada Dawood and his son Suleman.

Mr. Harding is a veteran of other extreme deep-water diving 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 is the Vice Chairman of Engro Corporation, a conglomerate that started as a fertilizer company.

Where exactly is the Titanic wreck?

Once the largest steamship in the world, the Titanic struck an iceberg four days after its maiden voyage, in April 1912, and sank to the bottom of the Atlantic Ocean. More than 1,500 people died.

It was discovered in pieces in 1985 about 400 miles from Newfoundland.

Seekers scan the sea.

The Coast Guard coordinated with Canadian authorities and commercial vessels to help search. Sonar buoys were deployed in the water and the expedition ship used sonar to locate the submarine.

Planes from the United States and Canada, along with surface craft, were scanning the waves in case the submarine had surfaced and communications were cut, a U.S. Coast Guard spokesman said.

But it is a very difficult quest.

A ship traveling to the Titanic is under crushing pressure during its long descent. At the ship’s resting place, the weight of the icy ocean pushing down would be equivalent to an overhead tower of solid lead rising to the height of the Empire State Building.

In search and rescue operations at sea, weather conditions, the lack of light at night, sea conditions and water temperature all play a role in finding and rescuing stricken sailors.

Rescuing people under the waves is even more difficult. Many underwater vehicles are equipped with an acoustic device that emits sounds that can be heard underwater by rescuers. It’s unclear if the Titan has one.

An additional danger could be that the vessel becomes stuck on a piece of wreckage, preventing it from returning to the surface.

If the submarine is found at the bottom of the sea, the extreme depths would limit possible rescue options. Divers wearing specialized equipment and breathing helium-rich air mixtures can safely reach a depth of only a few hundred feet below the surface before having to decompress for a long time on the way back. A few hundred meters deeper, the light of the sun no longer penetrates the water.

Typically, seekers and researchers looking into such inky depths rely on advanced robots using remote-controlled television, photography and sonar mapping systems that can survive the crushing pressure and pierce the darkness. But such exploratory work can be expensive and frustrating.

“We are doing everything we can do,” said Vice Admiral John Mauger, spokesman for the US Coast Guard.

Reporting contributed by William J. Broad, Emma Bubola, Amanda Holpuch, John Ismay, Jesus Jimenez, Victoria Kim, Salman Massood And Alan Yuhas.