The trip to the bottom of the ocean to see the world’s most famous shipwreck might be the adventure of a lifetime—even for the serial adventurer along for the ride, U.K. billionaire Hamish Harding—but questions are being raised about the craft that takes people to it. The Titan has never had an incident nearly as serious as the current one, but past reports about it show a history of rough waters.

The BBC, for example, quotes passengers from a 2022 dive, talking about problems with the Titan’s thrusters when they reached the ocean floor.

“Oh no. We have a problem,” submersible pilot Scott Griffith reportedly said.

One of the vehicle’s thrusters was thrusting backward instead of forward, which temporarily meant the craft could only rotate in a circle. The issue was resolved by holding the controller that steers the vessel—a modified Logitech F710 video game controller—in the opposite direction.

A CBS correspondent who made the journey last year saw one attempt scrubbed when a float came off the launch platform. And when the dive actually took place, communications between the sub and the surface ship broke down, resulting in the sub never finding the Titanic. (The ship is supposed to guide the sub to the shipwreck via text messages.)

“We were lost,” said passenger Shrenik Baldota. “We were lost for two and a half hours.”

David Pogue, the CBS reporter who went along on the journey, described the submersible as having “some elements of MacGyver jerry-riggedness. I mean, you’re putting construction pipes as ballast.”

OceanGate Expeditions CEO Stockton Rush pushed back on that description, saying “there are certain things that you want to be buttoned down. The pressure vessel is not MacGyver at all, because that’s where we worked with Boeing and NASA and the University of Washington. Everything else can fail, your thrusters can go, your lights can go. You’re still going to be safe.”