An old video tour of Titan - the submersible that went missing diving into the Titanic ruins - shows that the five passengers currently lost at sea are dealing with cramped conditions and low oxygen.
The tiny vessel has no seats, one tiny bathroom, and was likely navigated using a "video game controller."
All passengers have to sit on the floor, according to a BBC video from 2022 featuring OceanGate CEO Stockton Rush as he gives a tour of the submersible.
Rush is shown sitting on the ground while showing the video crew around - not that there was much around. The submersible has a small bathroom, one overhead light, a few wall lights, and a window. It is navigated using a video game controller that Rush waves in the air during the tour.
Usually, those are tolerable conditions, as the entire round trip on the submersible lasts eight hours, from launching from a boat until it surfaces.
It's been three days since Hamish Harding, Stockton Rush, Paul-Henry Nargeolet, Shahzada Dawood and his son Suleman went silent during a deep-sea dive that they had each paid $250,000 to undertake.
Mike Reiss, who joined OceanGate to glimpse the deteriorating wreck in 2022, said the trip is less tourism than it is true exploration — and the people who dare to try it are made well aware of the risks.
"You sign a massive waiver that lists one way after another that you could die on the trip," Reiss told the BBC in an interview Tuesday. "They mention death three times on page one. So it's never far from your mind. As I was getting on to the sub, that was my thought: That this could be the end."
David Pogue, a correspondent for CBS Sunday Morning, told the public in an interview that when he was on board the vessel last year for a tour as a member of the press, he "couldn't help noticing how many pieces of this sub seem improvised."
According to CEO Rush, Titan is special as it is one of the few underwater vessels like this that includes a private toilet for customers at the front of the sub. A small curtain is pulled across when it is in use, and the pilot turns up some onboard music.
The company's website recommends "you restrict your diet before and during the dive to reduce the likelihood that you will need to use the facilities," though. The interior lighting is from Camping World.
As a whole, the space inside is about the size of a minivan, not tall enough for someone to stand fully.
The only light source comes from wall-mounted lamps, and the sub has heat as the ocean is freezing. There is no word on how long those would last, considering the sub only has 96 hours of oxygen.
OceanGate admits that much of the interior consists of several pieces of "off-the-shelf technology," which "helped to streamline the construction and makes it simple to operate and replace parts in the field."
In a press release in 2019, the company explained why the Titan had not been classed by an independent body. "Bringing an outside entity up to speed on every innovation before it is put into real-world testing is anathema to rapid innovation," it said.
In a promotional video, OceanGate Expeditions software security expert Aaron Newman tells prospective clients that travelling on the sub is "not a ride at Disney, you know".
"There's a lot of real risk involved, and there's a lot of challenges," he says.
At this point, the undersea vessel has lost more than half of its oxygen.