American and Canadian authorities have stepped up the search for a missing submarine near the wreck of the Titanic.

According to the French news agency AFP, there are only a few hours left before the oxygen supply for the five people in the submarine runs out.

Coast Guard officials, on the other hand, say they are still ‘hopeful’ but still face the challenge of locating the submarine.

“Sometimes you’re in a position where you have to make tough decisions, but we’re not there yet,” said US Coast Guard Capt. Jamie Frederick.

“This is a search and rescue mission, one hundred percent,” he said.

The Canadian Air Force, Coast Guard ships and teleguided robots have participated in the operation. On Tuesday, rescue workers heard sounds in the North Atlantic, but it was not yet known what they were.

How long can a human live without oxygen?

Speaking with the Canadian newspaper ‘The Star’, Professor Bill Milson of the Department of Biology at the University of British Columbia said, “Usually, a person will pass out without oxygen for five minutes, and for 10 minutes or more.” A person dies due to lack of oxygen.’

“It is a difficult situation,” he said. Like everyone else, I’m hoping they find them in time and bring them back to the surface.’

On Sunday, the Titan submarine lost contact with the Polar Prince, an hour and 45 minutes after it began its journey.

The wreck of the Titanic lies under the sea about 400 miles off St. John’s, Newfoundland, Canada.

Billionaire tourist in Titan

The submarine Titan is carrying three tourists, including its pilot and CEO, including two Britons of Pakistani origin.

The fare per person for this tour is 250,000 dollars. Ocean Gate Expeditions takes tourists to the bottom of the ocean to see the wreck of the Titanic.