The Titan submersible which was taking tourists to see the wreck of the Titanic at the bottom of the Atlantic Ocean is believed to have run out of oxygen by now.
That's based off predictions by the US Coast Guard which is leading the search and rescue mission.
It suggested the oxygen for the five people on board would run out at 12.08pm Irish time.
The OceanGate expedition to see the wreck of the Titanic lost communication on Sunday and a rescue operation was launched.
Officials say they are "optimistic and hopeful" with 10 more ships and submarines due to join the operation today.
The search area now covers an area roughly half the size of Ireland and involves camera equipment scanning the sea floor.
Safety concerns were raised about the Titan in 2018; the Marine Technology Society said it had “concern regarding the development of Titan and the planned Titanic Expeditions” and warned against the “current experimental approach adopted by OceanGate”.
