A paid passenger on an expedition to the Titanic with the company that owned the Titan submersible testified before a U.S. Coast Guard investigatory panel Friday that the mission he took part in was aborted due to an apparent mechanical failure.

The Titan submersible imploded last year while on another trip to the Titanic wreckage site. A Coast Guard investigatory panel has listened to four days of testimony that raised questions about the company’s operations before the doomed mission.

Fred Hagen was first to testify Friday and was identified as a “mission specialist,” which he and other witnesses have characterized as people who paid a fee to play a role in OceanGate’s underwater exploration. He said his 2021 mission to the Titanic was aborted underwater when the Titan began malfunctioning and it was clear they were not going to reach the fabled wreck site.

The Titan appeared to be off course on its way to the Titanic, so the crew decided to use thrusters so the submersible could make its way to the wreck, Hagen said. The starboard thruster failed to activate, he said.

“We realized that all it could do was spin around in circles, making right turns,” Hagen said. “At this juncture, we obviously weren't going to be able to navigate to the Titanic.”

Hagen said the Titan dropped weights, resurfaced and the mission was scrapped. He said he was aware of the potentially unsafe nature of getting in the experimental submersible.

“Anyone that wanted to go was either delusional if they didn't think that it was dangerous, or they were embracing the risk,” he said.

OceanGate co-founder and Titan pilot Stockton Rush was among five people who died when the submersible imploded en route to the site of the Titanic wreck in June 2023.

Earlier this month, the Coast Guard opened a public hearing that is part of a high-level investigation into the cause of the implosion. The public hearing began Sept. 16 and some of the testimony has focused on problems the Washington state company had prior to the fatal 2023 dive.

During Thursday's testimony, company scientific director Steven Ross told the investigators the sub experienced a malfunction just days before the Titanic dive. Earlier in the week, former OceanGate operations director David Lochridge said he frequently clashed with Rush and felt the company was committed only to making money.

“The whole idea behind the company was to make money,” Lochridge testified. “There was very little in the way of science.”

The hearing is expected to resume next week and run through Sept. 27.

Other witnesses Friday included former OceanGate contractor Antonella Wilby, who worked in operations and engineering for the company. WIlby said she was criticized by company officials when she came forward about concerns about a banging noise during a 2022 submersible dive.

Hagen said during his own testimony that he feared the hull had cracked when he heard a loud bang during a 2022 dive. Wilby said OceanGate's director of administration told her “you don't seem to have an explorer mindset” after she raised the concern about noise.

She said she also never saw anyone inspect the sub's hull after the banging noise, which she described as similar to an explosion.

“I saw what I would classify as safety theater,” Wilby said.

Dave Dyer of the University of Washington Applied Physics Lab also testified Friday to provide details about the lab's relationship with OceanGate while its submersible was in development and said the company and lab disagreed about fundamental aspects of its engineering.

OceanGate felt it was better to terminate the relationship and take over the engineering itself, Dyer said.

“It was the engineering. We were butting heads too much,” Dyer said.

Another Friday witness, Triton Submarines chief executive officer Patrick Lahey, recounted meeting OceanGate personnel in 2019 and getting a look at their submersible when it was in development. He said he “wasn't particularly impressed” by what he saw.

Lahey stressed that it's important for submersibles to be accredited to ensure safety.

“I just said it looked to me like a lot of the stuff was not quite ready for primetime. And that there were many things in it that I thought had not been executed as appropriately as they should be,” Lahey said.

Lochridge and other witnesses have painted a picture of a company led by people who were impatient to get the unconventionally designed craft into the water. Lochridge said he filed a complaint with the federal Occupational Safety and Health Administration about the company. OSHA “promptly referred his safety allegations regarding the Titan submersible to the Coast Guard,” a spokesperson for the agency said Thursday.

The deadly accident set off a worldwide debate about the future of private undersea exploration. Coast Guard officials noted at the start of the hearing that the submersible had not been independently reviewed, as is standard practice. That and Titan’s unusual design subjected it to scrutiny in the undersea exploration community.

OceanGate suspended its operations after the implosion. The company has no full-time employees currently, but has been represented by an attorney during the hearing.

During the submersible’s final dive on June 18, 2023, the crew lost contact after an exchange of texts about the Titan’s depth and weight as it descended. The support ship Polar Prince then sent repeated messages asking if the Titan could still see the ship on its onboard display.

One of the last messages from Titan’s crew to Polar Prince before the submersible imploded stated, “all good here,” according to a visual recreation presented earlier in the hearing.

When the submersible was reported missing, rescuers rushed ships, planes and other equipment to an area about 435 miles (700 kilometers) south of St. John’s, Newfoundland. Four days later, wreckage of the Titan was found on the ocean floor about 330 yards (300 meters) off the bow of the Titanic, Coast Guard officials said. No one on board survived.

OceanGate said it has been fully cooperating with the Coast Guard and NTSB investigations since they began. The Titan had been making voyages to the Titanic wreckage site going back to 2021.