Email exchanges with a top deep sea exploration specialist demonstrate that warnings about the safety of OceanGate’s Titan submersible were frequently rejected by the company’s CEO.

Rob McCallum told OceanGate CEO Stockton Rush in texts obtained by the BBC that he was potentially endangering his clients and advised him to cease using the sub until it was classed by an independent body.

Mr Rush answered that he was “tired of industry players using safety as an excuse to stifle innovation.”

Mr McCallum said the heated exchange ended when OceanGate’s lawyers threatened legal action.

“I believe you may be putting yourself and your clients in a dangerous dynamic,” he wrote to OceanGate’s CEO in March 2018. “You are mirroring that famous catch cry, ‘She is unsinkable,’ in your race to [the] Titanic.”

Mr Rush, who was one of five passengers killed after the Titan encountered what officials suspect was a “catastrophic implosion” on Sunday, expressed irritation with the Titan’s safety procedures in the messages.

“We have heard far too many baseless cries of ‘you are going to kill someone,'” he stated. “I take this as a serious personal insult.”

According to Mr McCallum, he constantly pressed the business to acquire certification for the Titan before utilizing it for commercial tours. The ship was never certified or categorized.

“Until a submarine is classed, tested, and proven, it should not be used for commercial deep dive operations,” he added in an email.

“I implore you to exercise extreme caution in your testing and sea trials, and to be extremely conservative,” he added. “As much as I admire entrepreneurship and innovation, you may be jeopardizing an entire industry.”

Mr Rush responded a few days later, defending his company and credentials.

He stated that OceanGate’s “engineering focused, innovative approach… defies submersible orthodoxy, but that is the nature of innovation.”