As the world watches, time is running out for the five people missing in the Atlantic.
The adventurers set off from Canada on Sunday on a mission to view the Titanic wreck, but something went wrong during the two-and-a-half hours descent and contact with the submersible was lost.
A rescue operation was launched later that day, but search teams have been unable to locate the missing sub.
With experts revealing those inside the vessel only have enough oxygen to last until Thursday morning British time, we take a look at the doomed expedition...
TITAN SUBMERSIBLE
Titan is capable of reaching depths of 13,123ft or 4,000 metres, below sea level. It is made of titanium and carbon fibre and is the only submersible to use an integrated real-time health monitoring system which gives an early warning system should anything go wrong.
The walls of the sub are heated as conditions can become extremely cold at such extreme depths. Wall-mounted lamps are the only source of light on board.
There is a small porthole at the front of the vessel through which passengers can look at the wreck of the Titanic.
THE DIVING PLATFORM
The Titan begins its descent on a platform which floods its ballast tanks with water to descend to a depth of 9.1 metres, taking the vessel clear of any surface turbulence.
It then leaves the platform to descend the rest of the way.
At the conclusion of each dive, the sub ascends to land on the submerged platform and the entire system is brought to the surface in approximately two minutes by filling the ballast tanks with air.
THE CONTROLS
A modified Logitech gaming controller can move the vessel left, right, back, forward and up and down using four electric thrusters.
GPS doesn’t work at these depths, so the sub is guided by texts exchanged via a USBL (ultra-short baseline) acoustic system from a team on the surface vessel above.
The pilot steers based on these instructions with the video game controller.
3,800 METRES
Depth at which wreckage of the Titanic rests, the equivalent of 12 Shards (Britain’s tallest building) on top of each other.
WATER PRESSURE
It is estimated the pressure at the depth of the Titanic is 400 atmospheres– equivalent to 6,000 PSI (pounds per square inch).
The human body can withstand up to 400 psi if the weight is gradually increased.
THE LOCATION
The wreck of the Titanic lies off the coast of Newfoundland, Canada. It was located in 1985.
