The five billionaires who were aboard a Titanic submersible which went missing on Sunday are yet to be rescued.
On Tuesday, there were reports that a sound was heard deep in the ocean, but couldn't affirm that it was the submarine belonging to OceanGate.
The submersible
The OceanGate Titan watercraft can take up to five people to depths of up to 4,000m.
According to BBC, it is extremely narrow, measuring 670 cm x 280 cm x 250 cm. There is a private toilet, where a small curtain is pulled across when it is in use.
And before it begins its dive, the crew is locked inside. The supporting crew closes the hatch from the outside and seals it shut with 17 bolts.
According to OceanGate’s website, the Titan is used for site survey and inspection, research and data collection, film and media production, and deep-sea testing of hardware and software
According to the BBC, the five have few hours of oxygen remaining, and there is a race against time to find the sub. It is also reported that contact was lost just about two hours into their dive.
It is also believed that depending on conditions, some of those aboard could survive longer than expected.
"It depends on how cold they get and how effective they are at conserving oxygen," Ken LeDez, a hyperbaric medicine expert at Memorial University in St John's, Newfoundland told the BBC.
"Shivering will use up a lot of oxygen while wrapping up in a huddle can help to conserve heat."
"It's not like switching off a light, it's like climbing a mountain - as the temperature gets colder and metabolism falls [it depends] how fast you ascend that mountain," he said.
For the five to go deep into the ocean to visit the Titanic wreck for 8 days, they each paid a total of $250,000 (Sh35,100,000), with a themed slogan of 'become one of the few to see the Titanic with your own eyes.'
Their search is still underway.
Who are the five billionaires?
In the submersible, confirmed passengers are; Pakistani businessman Shahzada Dawood and his 19-year-old son Suleman Dawood and British businessman Hamish Harding.
Others are; French explorer Paul-Henri Nargeolet and the owner of the submersible and CEO of OceanGate Stockton Rush.
Paul-Henri Nargeolet
In the OceanGate website, Nargeolet is described as a Titanic expert, who has led six expeditions to the ship's wreckage site and is known as 'Titanic's Greatest Explorer'
CBS News reports that Nargeolet is the director of underwater research for RMS Titanic, an American company that owns the salvage rights to the wreck and operates exhibits featuring artefacts from the ship.
Stockton Rush
Rush is the CEO of the OceanGate a company he founded in 2009.
He is also the pilot of the missing submersible.
Hamish Harding
According to CBS News, Harding is the chairman of Action Aviation, which sells aircraft to international corporations, heads of state and people in the entertainment and sports industries.
He is referred to as a billionaire in the British press.
The businessman also holds several records with the Guinness Book of World Records, including the "fastest circumnavigation of Earth via both the geographic poles" by aeroplane, which he and a team accomplished in 2019 in a little over 46 hours.
Shahzada Dawood, and son Suleman
Shahzada Dawood is the vice chairman of Dawood Hercules, an investment and holding company based in Karachi, Pakistan.
Dawood is also an heir to one of Pakistan's largest family fortunes.
According to the Daily Mail, Suleman is a science fiction fan and also enjoys solving Rubik's Cubes and playing volleyball.
