Tourist submarine goes missing near Titanic shipwreck, massive search on to rescue 5 onboard

US and Canadian coast guard and navy search teams are racing against time to find a tourist submarine that went missing during a dive to the famous Titanic shipwreck on the floor of the Atlantic Ocean on Sunday.

The US Coast Guard said “a small submarine with five persons onboard” had gone missing in the vicinity of the Titanic wreck and that the vessel had the capacity to be submerged for 96 hours, but it was unclear whether it was still underwater or had surfaced and was unable to communicate, The Guardian reported.

The small submarine lost contact with the outside world around 2 hours after it dived down to visit the shipwreck.

As of Monday afternoon, it was thought those on board, including British billionaire and explorer Hamish Harding, had roughly four days of oxygen left, according to a BBC report.

“Right now, our focus is getting on as much capability into the area as we can,” Rear Adm John Mauger of the US Coast Guard told a press conference.

Military planes, a submarine and sonar buoys have so far been used in the search for the vessel.

The US Coast Guard said a research ship called the Polar Prince had conducted a surface search for the sub on Monday evening. It is used to transport submersibles to the wreckage site and was the support ship on Sunday’s tourist expedition.

The missing craft is believed to be tour firm OceanGate’s Titan submersible, which CBS journalist David Pogue travelled aboard last year to reach the wreckage of the Titanic.

Pogue told the BBC that when the support ship is directly above the submarine, short text messages are able to be sent between the two. Otherwise, communication via GPS or radio systems is not available as neither work underwater.

Pogue says it is also not possible for those aboard the submarine to escape by themselves because they are sealed inside by bolts applied from the outside.

Rear Adm Mauger noted the area in which the search was taking place was “remote”, making operations difficult. Added to this is the fact that visibility is quickly lost below the surface of the water as light cannot penetrate far.

The vessel weighs 10,432 kg and can reach depths of up to 13,100 ft, according to the OceanGate website.

Tickets cost $250,000 for an eight-day trip including dives to the wreck at a depth of 12,500 ft. Each full dive to the wreck, including the descent and ascent, reportedly takes around eight hours.

The Titanic, which was the largest ship of its time, hit an iceberg on its very first voyage from Southampton to New York in 1912. Of the 2,200 passengers and crew onboard, more than 1,500 died.