The world is watching, waiting and hoping for a happy outcome.
However, oxygen on the missing Titanic submersible is expected to run out in hours.
Rescue efforts to find the five people onboard in full force as hope fades of a successful rescue mission.
The loss of the vessel, named Titan, has captured the imagination of people around the world.
The vessel lost communication on Sunday while about 700km south of St John’s, Newfoundland, during a voyage to the Titanic shipwreck off the coast of Canada.
As of yesterday afternoon, it was thought just 20 hours of oxygen remained in the vessel, meaning it would run out at some point this morning.
Some of those on board have links to Ireland.
Experts have said that how long the air would actually last depended on various factors, such as whether the submersible still had power and how calm those aboard remained.
The 6.7m long OceanGate Expeditions vessel, which has British billionaire adventurer Hamish Harding on board, reportedly had a 96-hour oxygen supply in case of emergencies.
Also in the undersea craft are UK-based businessman Shahzada Dawood, his son Suleman Dawood, and OceanGate’s chief executive and founder Stockton Rush, reportedly with French submersible pilot Paul-Henri Nargeolet.
The US Coast Guard has been leading an international rescue effort which was stepped up after underwater noises were heard on Tuesday and again yesterday, although experts have been unable to determine the cause of the sound.
Former US Navy submarine commander David Marque, said the noises may not be coming from the submersible.
“I don’t think the noise is them, it could just be natural sounds,” he said.
“We’re hearing noises and more ships are coming into the area, and then we’re hearing more noises, and I don’t think that’s a coincidence.”
The US Coast Guard has been leading an international rescue effort with captain Jamie Frederick at the helm
One of the vessels sent to help search efforts is French research vessel L’Atalante which carries a remotely operated vehicle (ROV), Victor 6000.
This ROV has the capacity to lift the Titan ship to the surface.
Mr Marquet said he remains hopeful rescuers will find the vessel with the introduction of the ROVs.
The area of the search has been expanded, with the surface search now about 25,900sq/km, and the sub-surface search about 4km deep.
