An ocean expert believes the missing Titan submersible may have become snared on part of the Titanic's wreckage.
The tourist submersible is still missing with five onboard since Monday, when the vessel lost connection on it's dive to the wreck of the Titanic.
The area of the Atlantic Ocean they're looking in is extremely remote, 900 miles off America's East Coast and about 370 miles off Newfoundland in Canada.
The Boston Coastguard is now responsible for the critical search mission, and it'll be a race against time as the vessel's oxygen supplies are set to run out by Friday morning.
Southampton University's Oceanography professor Dr Simon Boxall spoke to Ingrid Hipkiss.
