A father who gave up on a seat on the submersible that vanished on a mission to see the wreckage of the Titanic says the firm's CEO flew out to convince him to buy tickets.
But this raised enough concerns for Jay Bloom, a financier who had considered buying tickets for himself and son Sean, and confirmed his decision not to go on the trip.
OceanGate Expeditions CEO Stockton Rush, who coordinated the voyage, flew to Las Vegas to convince Mr Bloom aboard an "experimental plane".
"It was very concerning. The major red flag for my son was when Stockton came to see me in Las Vegas in March," Mr Bloom told NewsNation.
"He said he was flying in in a two-seater experimental plane that he built so he was coming to Las Vegas on an experimental plane that he built to take me on an experimental sub that he built to take me to the bottom of the Atlantic ocean."
Mr Bloom had previously shared texts between himself and Mr Rush showing how he and his son were offered a "last-minute price" of $150,000 (£117,000) a head to take the voyage.
The dad added: "It's kind of surreal. Every time I see a picture of the people who lost their lives on this tragic event.
"I look at the picture of the father and son who replaced my son and myself and think how easily but for the grace of god that could have been our picture on the news.
"When Stockton first approached me with the idea it sounded very sexy, very exciting, a real bucket list kind of item.
"My son is a big fan of the Titanic, so I thought it would be great for us to do something together. The allure of the proposition is so compelling.
"My son talked to his friend and they voiced concerns, about the vessel, the marine life, some of the materials that were used in the construction."
Mr Bloom's seats went instead to Shahzada Dawood and his 19-year-old son, Suleman Dawood, two of the other three who lost their lives on the excursion.
The sub lost communication with its operator, OceanGate Expeditions, less than two hours into its dive to the shipwreck last Sunday, with five people on board.
A large-scale rescue operation including planes and a fleet of vessels had been scrambled to the area 400 miles southeast of Newfoundland, Canada, as oxygen supplies in the sub dwindled.