In the Atlantic Ocean, the search for a submarine en route to the Titanic continues for a second day

American and Canadian rescuers are struggling against time for the second day to locate a tourist submarine that vanished in the Atlantic Ocean en route to the wreckage of the Titanic. Five people were onboard and contact was lost an hour and 45 minutes after submerging on Sunday morning, according to CNN.

If the submersible remained intact, those aboard would have encountered depleting oxygen levels and battled against the cold, as the deep ocean water temperature is just above freezing, stated David Gallo, Senior Advisor on Strategic Initiatives for RMS Titanic Inc., the company that holds exclusive rights for rescue operations at the Titanic's sinking site.

Upon finding the submersible, the team may face even greater challenges in attempting to rescue the crew.

"The water is incredibly deep — over 2 miles. It's like a visit to another planet; it's not what people envisage. It's a sleepless, cold environment under high pressure," added Gallo.

One thing is to get there, another is to "understand the situation regarding the problem with the underwater link, then get to work trying to extract it from there," clarified the expert.

It's still unclear what happened to the missing submarine, why it lost contact with the surface crew, and where or at what depth it might be.

Eric Fusil, an expert on submarines and an adjunct professor at the University of Adelaide, said that search operations are complicated by the limited underwater communication methods with the submersible.

Government agencies, naval forces from both countries, and deep-sea exploration companies are participating in the rescue, but so far there are no signs of the 6.7-meter vessel. It's believed that as of yesterday, there was enough oxygen left onboard to last the crew another four days.

As reported yesterday, the crew comprises a pilot and four "mission operators."

One of them is British billionaire, explorer, and adventurer Hamish Harding (59), who announced on social media over the weekend that he was embarking on an expedition.

The Titanic's wreckage lies about 3800 meters deep, 700 kilometers south of St. John's, although the rescue operation is being conducted from Boston. The search involves military aircraft, a submarine, and sonar equipment.

"The area being searched is remote, which further complicates the operation. Visibility is lost right below the water's surface," said Admiral John Moger from the US Coast Guard.

The missing Titanic submarine belongs to the company Oceangate, which arranges trips to the Titanic for $250,000 per seat.

To remind, in May, scientists and researchers, using 70,000 photographs, created a digital precise replica of the Titanic, which sank after colliding with an iceberg in 1912. The disaster claimed the lives of more than one and a half thousand people.