Doctor shares what missing Titanic submarine crew will face as they run out of oxygen

A doctor specialising in medicine in extreme conditions has shared what he believes the group aboard the Titan submersible face if the oxygen runs out before they can be rescued.

Dr Kenneth Ledez, a Hyperbaric Medicine Specialist at Memorial University in Newfoundland, Canada, says the group may have to be "carried out" and won't be able to rescue themselves.

He explained: "Well I mean, even if they are rescued. Let's say they are rescued after the oxygen levels drop too low., they are not going to be able to rescue themselves, they will have to be carried out.

"And depending on how long and how low the oxygen has been will determine, you know, what the long-term outcome is.

"Can people survive after exposure to those conditions? Yes they could have damage to the nervous system or heart and extended time.

Dr Kenneth Ledez, the director of Centre for Offshore and Remote Medicine (MEDICOR) and Medical Director of Hyperbaric Medicine in St John's, Newfoundland (BBC)

"So really it's going to be a gradual deterioration."

He told the BBC that the search effort needs to continue in the hopes of getting them to the surface in time.

The doctor said there are a special set of considerations due to the difficulty in controlling their interior environment.

"But if they're still alive, they are doing everything they possibly can do now. To survive," he told the broadcaster.

"They're smart and they know the steps that they got to make."

The submersible is still missing (Anadolu Agency via Getty Images)

The race is on to find the submarine as quickly as possible, with a fleet of vessels gathering at the search site in the hopes of finding them before their oxygen runs out at 12.08pm.

But David Gallo, who has been involved in countless deep sea missions himself, says that an act of God will be needed to save the Titan, but that he is still optimistic.

Speaking to Good Morning Britain, he said the noises were "credible and repeatable", meaning it's likely the group are somehow making those sounds.

The Titan vessel bounces on the surface of the sea (PA)

He added that the operation needs to assume that they are being created by the men on board, pinpoint it and drag them to the surface.

"We have to, at this point, assume that that's the submarine and move quickly to that spot, locate it and get robots down there to verify that is where the submarine is," he said.

"They've got to go fully ready as if that was the sub because to locate it and get it up to the surface - it takes hours."