Mashable: A tourist submarine went missing in the mid-Atlantic ocean, while it was taking a group of five people to see Titanic's wreck on Sunday, reports BBC. The last contact was made with it an hour and 45 minutes after it dove.
US and Canadian authorities are panicking as there is no sign of the vessel so far. Moreover, the countries have sent search and rescue teams to get the tourists back safely, which includes the efforts of the countries' navies and commercial deep-sea firms.

On Monday, it was calculated they have four days worth of oxygen left in the vessel. Of the five people, one person on the ship is British billionaire businessman and explorer Hamish Harding.

According to The Associated Press, Harding was the mission's specialist, who wanted to conduct research at the wreckage site. He also has three Guinness World Records due to his successful mission with the longest duration at full ocean depth by a crewed vessel. Previously, he and Victor Vescovo, another ocean explorer, went to the lowest depth of the Mariana Trench.

Rear Adm John Mauger, a member of the US Coast Guard, revealed in a press conference that their focus is "getting on as much capability into the area as we can.

The search and rescue team has employed military planes, a submarine and sonar buoys. They also used another research ship known as Polar Prince on Monday evening as it can move submersibles to the wreckage site. It was also supposed to be a support ship for the expedition.

The missing vessel belongs to ceanGate's Titan submersible, which also helped David Pogue, which CBS journalist, see the Titanic last year.

Pogue revealed to BBC a support ship helps to send texts between the two vessels, as GPS or radio systems do not work underwater or are not available. Moreover, people inside the submarine can't leave the vessel, as they are sealed inside via bolts, which can only open from the outside.

The area where the search is taking place is "remote", which makes everything difficult, reveals Rear Adm Mauger. In addition, one can't see things clearly once they are below water as light can't penetrate deep water.

OceanGate has three submarines, of which, the Titan is the one that can dive deep to reach the wreckage site. The submarine has a weight of 10,432 kg and can reach 13,100 ft of oceanic depth. The cost of $250,000 is set for an eight-day trip to the underworld, which includes Titanic's wreck located at 12,500ft depth.

According to Harding's post, this was the first, and perhaps, the only human member mission to the Titanic due to the worst winter of the region in four decades.
OceanGate's website also reveals that the submarine begins its sail from St John's in Newfoundland, and it takes about eight hours to dive to the wreck, and while returning from it.