OceanGate's Stockton Rush said he took it as a 'serious personal insult' when a former advisor warned him about the Titanic sub's risks, and threatened to sue when the consultant declined to work for OceanGate: report

• Stockton Rush once bristled in 2018 when warned that his Titanic submersible posed safety risks.
• Rush called warnings from other industry players a "serious personal insult," per The New Yorker.
• Rush also threatened to sue a former advisor who sent him a cautionary email, the outlet reported.

OceanGate CEO Stockton Rush said he felt personally insulted when a fellow submersible enthusiast and expedition consultant cautioned in 2018 that the Titan wasn't ready for commercial deep-sea tours.

Rob McCallum, the cofounder of EYOS Expeditions and a former advisor to OceanGate, emailed Rush in March 2018, warning him that he was using a "prototype un-classed technology in a very hostile place," reported The New Yorker's Ben Taub.

"As much as I appreciate entrepreneurship and innovation, you are potentially putting an entire industry at risk," McCallum warned Rush, per Taub.

Rush responded four days later, complaining of "industry players who try to use a safety argument to stop innovation and new entrants from entering their small existing market," Taub reported.

Rush said that his vessel's technology "flies in the face of submersible orthodoxy, but that is the nature of innovation," according to Taub.

"We have heard the baseless cries of 'you are going to kill someone' way too often. I take this as a serious personal insult," Rush wrote.

Rush's response also came after a cofounder of Triton Submarines, a company that also makes deep-sea submersibles, wrote days before to OceanGate with a warning that people could die in the Titan.

McCallum worked with Triton to lead at least one expedition to the Titanic shipwreck. Triton's submersible, unlike the Titan, was certified to reach extreme depths by the marine society DNV. Apart from this expedition, McCallum also twice took tourists to see the Titanic — which is around 13,000 feet underwater — using submarines that were rated to reach 19,000 feet.

McCallum wrote back to Rush after the OceanGate CEO's irate email, and listed several of his concerns with the Titan, per The New Yorker.

"In your race to Titanic you are mirroring that famous catch cry 'she is unsinkable,'" the expedition leader wrote, according to the outlet.

Taub reported that Rush then asked McCallum to work for OceanGate, and that when the latter declined, he was threatened with a lawsuit from the CEO.

They stopped emailing each other afterward, Taub reported. McCallum previously advised OceanGate on marketing and logistics, and visited its Seattle workshop as it was working on the Cyclops I, the predecessor to the Titan.

His exchange with Rush also happened about two months after OceanGate fired its chief submersible pilot, David Lochridge, who said in a lawsuit that he was terminated after raising safety issues with the Titan's hull.

Lochridge said one of his key concerns was that the submersible didn't have a proper system to alert OceanGate if the hull — made from an unusual mix of carbon fiber and titanium — was suffering from issues that could lead to a breach.

OceanGate started running its annual tours to the Titanic in 2021, and was deploying the Titan on its third commercial expedition when it disappeared on June 18. 

The authorities later announced that the Titan likely imploded thousands of feet underwater, after remote vehicles found debris of the submersible on the sea floor.

Rush, who died aboard the submersible, has since come under the spotlight for his previous comments criticizing industry safety regulations and amid emerging reports that he ignored warnings from other experts. However, the CEO's colleagues and close friends have defended him, saying he prioritized safety above ambition.

OceanGate did not immediately respond to a request for comment sent outside regular business hours.