(NewsNation) — The host of the popular Discovery show “Expedition Unknown” opted out of a deep-sea dive on OceanGate’s Titan submersible because of what he said was a lack of available safety data.

Josh Gates got his first look at the sub during a test run in 2021, just months before the company began taking passengers down to the Titanic.

“By the end of the trip, I really just came to the conclusion that this wasn’t for me, and I’m not a guy who says no to dangerous things very easily,” Gates said Thursday on “CUOMO.”

He’s one of many that have voiced questions about the safety and construction of the vessel, which is made of carbon fiber.

Calling it a “one-off” vehicle, Gates’ chief concern is that there was nothing to benchmark the Titan against. Other submersibles, he said, are built using a titanium or steel-alloy pressure sphere.

“Carbon fiber is a miraculous material … and it can be 10 times stronger than steel, but it has to be engineered to really exacting specifications,” Gates said. “There are a lot of mysteries about how this material performs at incredible pressure … and there just was no data here to measure against. So, for me, it was like you couldn’t even assess the risk.”

Search-and-rescue crews found remnants of the Titan on the ocean floor Thursday, suggesting it imploded as it neared the Titanic wreckage. Authorities were still piecing together a possible timeline of when the disaster occurred.

On board the craft were OceanGate CEO Stockton Rush, Titanic expert Paul-Henri Nargeolet, British billionaire Hamish Harding, Pakistani businessman Shahzada Dawood and his son, Suleman.

Gates lauded the work of explorers who he said should be given “admiration for their courage” in testing the limits of man. However, he said that at some point, hard questions will have to be asked about the design and development of Titan.

“I do think that the idea of taking risks and exploring and being part of an adventure, those things I think are actually kind of critical to the human condition, but as we’ve seen here today, those things also can come at a very high cost,” Gates said.