Rescue ship Deep Energy has arrived in the middle of the Atlantic after a "banging" noise was heard from the Titan vessel on Tuesday, according to the US Coast Guard.
The ship is deploying remote operated submarines to try and find the Titan and rescue the five passengers on board the OceanGate Expeditions wreckage tour submarine. Two US Lockheed C-130 Hercules aircraft were conducting overflights, and three C-17s from US Air Mobility Command have also been used to move another commercial company's submersible and support equipment from Buffalo, New York, to St. John's to aid in the search.
"That's why it's so important that we've engaged experts from the Navy that understand the science behind noise and give us better information about what the source of that noise may be. In the meantime, it's a target - a focus - for us, to look at." Coast Guard Captain Jamie Frederick told reporters on Tuesday the passengers had "about 40 hours of breathable air left" - which was an estimate based on the vessel's original 96 hours of available oxygen.