US Coast Guard: Crew, passengers of missing Titanic adventure sub now has just 41 hours of oxygen

U.S. Coast Guard Capt. said Tuesday those aboard the submersible gone missing during a dive on the Titanic shipwreck now have just roughly 41 hours left of oxygen. 

A Coast Guard-led search-and-rescue effort began Sunday for the five men aboard the OceanGate's 21-foot Titan submersible.

The craft went missing about 900 miles east of Cape Cod, Massachusetts, on an expedition to explore the wreckage of the Titanic.

The Titan had enough oxygen to keep the five crew members alive for about 96 hours beyond the dive, which means as of 1 pm ET on Tuesday, they only have 41 hours till the air on board is no longer breathable.

On Tuesday the Coast Guard said in a news conference that have been "searching 7600 square miles –basically the size of Connecticut." More vessels are on the way to help the search the Coast Guard reported.

U.S. Coast Guard Rear Adm. John Mauger said on Monday that to do a “comprehensive sonar survey of the bottom” the agency requires equipment they do not have.

'We’re really just focused on trying to locate the vessel again by saturating the air with aerial assets, by tasking surface assets in the area, and then using the underwater sonar," he told Fox News. 

Jannicke Mikkelsen, a friend of Hamish Harding, 58, who's trapped on the Titan, said that the craft is “a self-rescue vessel” with seven systems that unload weight so, if it needs to, it can rise to the surface by itself.

“The only way it couldn't do that," Mikkelsen said, "is if it was trapped — for instance, in the wreck of the Titanic or maybe as something as simple as a fishing net,” CNN reports.

Harding has experience in extreme circumstances, holding the world record for longest time spent at full ocean depth on a visit to the Mariana Trench.

Harding has also been to the South Pole, with astronaut Buzz Aldrin, and to space – without Aldrin — on Blue Origin's fifth human crewed flight. 

Another on board is Paul-Henry Nargeolet, 77, who was aboard the first manned expedition to visit the wreck of the Titanic and has spent more time around it than then anyone else.

Nargeolet also reportedly directs the underwater research team at a company that own the rights to the wreck.

Two others among those aboard are one of Pakistan's richest men, Shahzada Dawood, 48, and his son Sulaiman Dawood,19. 

"We are very grateful for the concern being shown by our colleagues and friends and would like to request everyone to pray for their safety while granting the family privacy at this time," the Dawood family reportedly said in a statement. "The family is well looked after and are praying to Allah for the safe return of their family members."

The fifth member reportedly aboard the Titan is Stockton Rush, who is the chief executive of OceanGate, the company who runs this now lost $250,000-a-ticket expedition.