While Cameron is known for his work on films like The Terminator, Avatar, and Titanic, the director is also a deep-sea explorer. Cameron is one of a handful of people to have visited the so-called Challenger Deep, the deepest-known-point on the Earth’s seabed, almost threefold deeper than the resting place of the Titanic.

In multiple interviews on Thursday, Cameron said he was concerned about OceanGate’s use of a carbon fiber composite for the hull of its submersible. OceanGate had earlier argued that carbon fiber—used in aerospace manufacturing—would be cheaper than a fully metallic hull. 

Yet a carbon fiber composite is “completely inappropriate for a vessel that sees external pressure,” Cameron said on CNN. Such material might see “progressive damage” over time despite successful dives, he continued. 

OceanGate’s use of sensors to determine when the hull was at risk of failing was also a mistake, said Cameron on CNN. “It sheds a light directly on the fundamental flaw of their design.”

The film director said he had warned other would-be explorers against using submersibles made using composite materials, telling one such owner, “You’re going to die down there, if you dive that thing.”

“I wish I’d spoken up, but I assumed somebody was smarter than me, you know, because I never experimented with that technology, but it just sounded bad on its face,” Cameron told Reuters.

OceanGate and its representatives did not immediately respond to a request for comment. 

Tourist submersibles

The director had harsh words for OceanGate CEO Stockton Rush, confirmed to have perished by the company on Thursday. OceanGate had criticized the certification process for submersibles, claiming in a 2019 blog post that “bringing an outside entity up to speed on every innovation before it is put into real-world testing is anathema to rapid innovation.”

“You can’t take that stance when you’re putting paying customers into your submersible—when you have innocent guests who trust you and your statements,” Cameron told the New York Times.

OceanGate had dismissed earlier warnings about its submersibles. In 2018, the company’s former director of marine operations sued the company, alleging wrongful dismissal after he’d raised concerns about the Titan’s ability to withstand the pressure of a deep-sea dive. The suit was settled out of court. 

In a YouTube interview in 2021, Rush noted that he had “broken some rules” of submersible design with his vessel, but claimed that innovation was “picking the rules that you break, that are the ones that will add value to others and add value to society,” according to Insider. 

In a television interview on Thursday, Cameron compared OceanGate’s lost submersible to the decision that led to the sinking of the Titanic in the first place, noting that “warnings went unheeded.”

“I’m struck by the similarity of the Titanic disaster itself, where the captain was repeatedly warned about ice ahead of his ship, and yet he steamed at full speed into an ice field on a moonless night,” Cameron said on ABC News. 

Cameron is himself an investor in commercial ocean exploration, as a part-owner of Florida-based Triton Submarines, which makes and sells submersibles for personal, commercial, and scientific use. 

“These are serious people with serious curiosity, willing to put serious money down to go to these interesting places,” Cameron said on CNN. “I don’t want to discourage that.”

The Titan’s fate

On Thursday, authorities announced they had discovered debris from OceanGate’s Titan submersible, one-third of a mile from the Titanic shipwreck. The debris was consistent with a “catastrophic implosion.” OceanGate later confirmed the deaths of the Titan’s passengers, including its CEO, Rush.

A secret U.S. Navy system to monitor enemy submarines heard sounds consistent with an implosion soon after the Titan lost communications on Sunday evening, reports the Wall Street Journal.

OceanGate, in its statement, called the Titan’s five passengers “true explorers who shared a distinct spirit of adventure, and a deep passion for exploring and protecting the world’s oceans.”