The desperate search for a missing submersible near the wreck of the Titanic entered a critical juncture on Thursday when air was expected to run out for the five people aboard, but officials vowed to continue scouring the remote North Atlantic.
Five days since the Titan began what should have been a two-hour dive to the century-old shipwreck, a massive multinational hunt over thousands of square miles was still expanding.
A remotely operated vehicle deployed from a Canadian vessel reached the ocean floor to begin searching, the U.S. Coast Guard said on Thursday morning, while another robotic craft from a French research ship was also preparing to dive to the seabed.
Also read: Pakistani businessman on lost submersible with 4 others once survived nightmarish plane journey
The minivan-sized Titan, operated by U.S.-based OceanGate Expeditions, began its descent at 8 a.m. (1200 GMT) on Sunday but lost contact with its support ship.
The submersible set off with 96 hours of air, according to the company, which means the oxygen would be exhausted by Thursday morning, assuming the Titan is still intact. Precisely when depends on factors such as whether the craft still has power and how calm those on board are, experts say.
Also read; How did the submersible, with two Pakistanis on board, go missing near Titanic wreck?
Rescuers and relatives of the Titan’s five occupants took hope when the U.S. Coast Guard said on Wednesday that Canadian search planes had recorded undersea noises using sonar buoys earlier that day and on Tuesday.
But remote-controlled underwater vehicles searching where the noises were detected had not yielded results, and officials cautioned the sounds might not have originated from the Titan.
Despite the fading hopes, U.S. Coast Guard rear admiral John Mauger told broadcaster NBC the search would continue throughout Thursday.
The French research ship Atalante, equipped with a robotic diving craft capable of reaching where the Titanic lies about 12,500 feet (3,810 metres) below the surface, had arrived in the zone as of Thursday.
It was first using an echo-sounder to accurately map the seabed for the robot’s search to be more targeted, the French marine research institute Ifremer said.
The robot, Victor 6000, has arms that can be remotely controlled to help free a trapped craft or hook it to a ship to haul it up. The U.S. Navy is sending a special salvage system designed to lift large undersea objects.
