This is what will happen to crew as oxygen starts running out on Titanic sub

As air supply dwindles on the Titan submarine, an expert has revealed what will happen to those aboard the missing vessel.

It vanished on Sunday morning off the coast of Newfoundland, Canada, where it had been completing an exploratory dive around the Titanic shipwreck.

Despite being equipped with 96 hours of oxygen, the ship’s air supply is set to run out later today (22 June).

Rescue teams are still searching for the OceanGate submarine, with the US Coast Guard being heavily involved in the extensive search.

Currently, they are investigating a remote part of the Atlantic Ocean which is estimated to be twice the size of Connecticut.

Trapped beneath thousands of feet of water in the pitch black, it’s likely that the missing men will have begun to feel the effects of oxygen deprivation.

As this dwindles, the amount of carbon dioxide in the small sub and their bloodstream will also increasing - leading to a fatal condition: hypercapnia.

According to Dr Ken LeDez, who is a hyperbaric medicine expert Memorial University in St John's in Newfoundland, those onboard may already have the condition.

If left untreated, those affected will become drowsy as the final hours of air supply pass by.

"As levels of carbon dioxide build up, then it becomes sedative, it becomes like an anaesthetic gas, and you will go to sleep," he explained to the BBC.

He added that it would be a gradual process, explaining: "It's not like switching off a light, it's like climbing a mountain - as the temperature gets colder and metabolism falls [it depends] how fast you ascend that mountain."

He also said some of the men could survive longer than others, saying 'it depends on how cold they get and how effective they are at conserving oxygen'.

The air supply is estimated to run out around 11am (UK time), with the desperate search still ongoing.

OceanGate

Teams are trying to pinpoint a ‘banging’ sound which was heard on Tuesday night – close to the Titan’s last known location.

During yesterday’s press conference, however, Captain Jamie Frederick said that he ‘doesn’t know’ what the sound was.

"We don't know what [the noises] are, to be frank with you," the US coast guard pointedly told press, adding: "We're searching in the area where the noises were detected."

While he insists that they ‘need hope’ and that submersible robots are being deployed in the area, the sub and five people remain unaccounted for.

The four passengers include British billionaire explorer Hamish Harding, Pakistani businessman Shahzada Dawood and his 19-year-old son Suleman, as well as OceanGate’s CEO Stockton Rush.

Experienced French diver Paul-Henry Nargeolet is also onboard and was the only crew member during the vessel’s sudden disappearance.