The Oceangate submersible Titan was lost in June 2023 en route to the wreckage of the Titanic. Debris has been found and the coast guard reported that the vessel catastrophically imploded, killing everyone on board.
Five people were in the submersible: Stockton Rush, the founder and chief executive of OceanGate Expeditions, which operated the vessel; Hamish Harding, a British businessman and explorer; another British businessman, Shahzada Dawood and his son, Suleman, from one of Pakistan’s wealthiest families; and Paul-Henri Nargeolet, a French maritime expert who had been on more than 35 dives to the Titanic wreck.
Many news and social media shares have referred to this expedition as "billionaire tourism", but I am skeptical that any of the people involved were actually billionaires.
Hamish Harding
Sky News has referred to Harding as a billionaire.
Insider calls Harding a billionaire.
These sources refer to Action Aviation as Harding's source of wealth, a company that sold 30 aircraft in 2021 and owned four as of December 2022. I'm skeptical that this company is successful enough to propel anyone to billionaire status.
A Forbes article states
Harding’s exact net worth is unknown. Some British outlets, including the Telegraph, refer to Harding as a billionaire. However, Harding does not feature on Forbes’ list of billionaires.
Shahzada Dawood
CNN referred to the Dawoods as "a billionaire father and son duo".
PKBnews claimed that Dawood is "a multibillionaire" in 2021.
Distractify states that "it's safe to assume the businessman is worth several billion dollars as he comes from one of Pakistan's wealthiest families."
The Statesman reports $350 million.
Dawood's wealth seems to be intertwined with that of his father, Hussain Dawood, a chair on several large Pakistani companies.
No Dawood appears on Forbes's billionaires list.
Paul-Henri Nargeolet
Most incredibly of all, fresherslive claims that Nargeolet has a net worth of $1.5 billion, "through his notable career as the Director of the Underwater Research Program at Premier Exhibitions, RMS Titanic, Inc".
Several other sources including Yahoo have reported the same number, but it's difficult to track how many of them are making an independent report and how many are reporting on an article from another site (like Yahoo is).
Premier Expeditions went bankrupt in 2016, appears to have had maximum yearly revenues in the single digit or low double-digit millions, and had their entire collection of Titanic artifacts valued at $20 million in 2018. Nargeolet is not claimed to be a CEO or owner of this company, only a diver and director of the underwater program. I'm skeptical that this level of involvement with this size of company would lead to a wealth in the billions.
Nargeolet does not appear on Forbes's billionaires list.
Stockton Rush
The net worth of OceanGate's founder and CEO is also highly variable, with sources reporting between $12 million and $50 million, but none claim he is a billionaire.
Summary
Is there any credibility to the claims that there was a billionaire (or even multiple billionaires) onboard the downed Titan sub?
None of the five people involved appear on Forbes's billionaire list.