Titan, operated by OceanGate Expeditions, is a commercial undersea vessel that takes individuals like doctors, artists, researchers, biologists, and divers down to the world's most famous shipwreck site - the ruins of the Titanic.
Tours to the 'unsinkable' sunken ship are quite common now, as Titan has been operating for over a year.
"Titan is the only five-person sub capable of going to the Titanic depth, which is half the depth of the ocean," said Stockton Rush, founder and CEO of OceanGate.
"There's no switches and things to bump into, we have one button to turn it on. Everything else is done with touch screens and computers, and so you really become part of the vehicle and everybody gets to know everyone pretty well," adds Rush in an interview with CBC last year.
OceanGate’s website, accessible via the Internet Archive’s Wayback Machine, lays out what passengers can expect on the $250,000 trip.
“Follow in Jacques Cousteau’s footsteps and become an underwater explorer — beginning with a dive to the wreck of the RMS Titanic. This is your chance to step outside of everyday life and discover something truly extraordinary,” the website said. “Become one of the few to see the Titanic with your own eyes.”
The eight-day expedition is based out of St. John’s, Newfoundland, Canada, with a maximum of six people. The trip begins with a 400-nautical-mile journey to the wreck site.
Up to five people, including a pilot, a 'content expert' and three paying passengers, board the submersible named 'Titan' and descend to the bottom of the ocean.
“Once the submersible is launched, you will begin to see alienlike lifeforms whizz by the viewport as you sink deeper and deeper into the ocean. The descent takes approximately two hours but it feels like the blink of an eye,” the website said.
Their submersible has lost contact and gone missing for the first time, triggering an international search effort in the water.
One British man is feared missing - with up to five people thought to include Hamish Harding, are trapped underwater as the US Coastguard tonight were in a race against time to find the vessel.
The crew, reported lost this morning, has an oxygen supply able to last 96 hours.
British explorer Harding is part of the expedition.
Still, it has yet to be confirmed if he is on the submersible despite saying he was part of those set for the ocean floor.
OceanGate Expedition has confirmed that it is their vessel at the centre of the rescue mission and that an unknown number of crew members are on board.
The company said it is “exploring and mobilising all options to bring the crew back safely.”
“Our entire focus is on the crew members in the submersible and their families,” said OceanGate, adding that it is “deeply thankful for the extensive assistance we have received from several government agencies and deep sea companies in our efforts to reestablish contact with the submersible.”
OceanGate Expedition did not say how many people were on board the missing vessel or whether any of them were paying tourists.
Britain, France and Norway run Nato’s global submarine rescue service, which can only dive to 610 metres.