Passengers stuck in Titanic sub have no way out of vessel unless they're found

The five passengers who went missing in a submersible in the Atlantic ocean have no way out of the vessel unless authorities manage to track it down.

Details are continuing to emerge about the missing vessel, known as Titan, after authorities lost contact with it about an hour and 45 minutes after it began its dive on Sunday (18 June).

With five people on board, the submersible descended below the water's surface to explore the wreck of the Titanic.

The venture is part of of an eight-day trip run by tour firm OceanGate, with tickets costing $250,000 (£195,000).

The hefty price tag means not everyone will be able to afford a seat on the submarine, but one person who has previously been on an expedition involving the Titan is CBS News correspondent David Pogue, who released a report on his experience in November.

Pogue spoke again about the makeup of the vessel after the Titan went missing, telling the BBC that neither GPS nor radio work underwater, meaning there's no way for rescuers on land to communicate with the vessel if it's still submerged.

"When the support ship is directly over the sub, they can send short text messages back and forth. Clearly those are no longer getting a response," Pogue explained.

Pogue believes Titan has at least seven functions which can help bring it to the surface, but there's no solution if it starts leaking, or gets trapped underwater.

"There's no backup, there's no escape pod. It's get to the surface or die," he said.

OceanGate

However, even if the crew are able to make it to the surface, the passengers inside the vessel have no way of opening it themselves from the inside.

"The crew closes the hatch, from the outside, with 17 bolts. There's no other way out," Pogue said in his November report.

Elaborating, Pogue told the BBC: "There's no way to escape, even if you rise to the surface by yourself. You cannot get out of the sub without a crew on the outside letting you out."

It's understood that Titan has a 96-hour oxygen supply in case of emergencies, meaning the clock is ticking if the passengers are trapped inside.

It typically takes Titan around two hours to descend approximately 12,500ft below the surface to where the Titanic lies in a trench.

Rear Admiral John Mauger, of the US Coast Guard, has said responders are 'deploying all available assets' to locate the vessel.

However, he added: "It is a remote area and it is a challenge to conduct a search in that remote area."