The Titan sub has a history of malfunction, German adventurer Arthur Liobl told German media outlet Bild, describing his experience on the missing submarine the Titan in 2021.
Liobl made the voyage alongside 73-year-old Paul-Henry Nargeole, an expert in shipwrecks, and 61-year-old Stockton Rush who is the CEO and founder of Oceangate, the submarine company that is responsible for Titan voyages.
Both Nargeole and Rush are onboard the missing Titan with three other passengers.
"It was a suicide mission back then!" Liobl told Bild.
Liobl had booked the trip having already experienced the rush of flying over Russia in an MiG-29 fighter plane and visiting both the North and South Pole. Despite his history of adventure, Liobl said that "The Titanic was the most extreme" trip he had taken.
“The first submarine didn't work, then a dive at 1,600 meters had to be abandoned. My mission was the fifth, but we also went into the water five hours late due to electrical problems,” Liobl explained, adding that he believed this could have been the cause to the subs current malfunction.
During his own trip, the bracket of a stabilization tube, which was responsible for the sub's balanced descent, allegedly tore. “That was reattached with zip ties. That didn't worry me," he expressed.
It has now been revealed that concerns over the Titan's safety were raised in 2018.
Conditions aboard the Titan
"You need strong nerves, you mustn't be claustrophobic and you have to be able to sit cross-legged for ten hours," Loibl said about the trip.
"It must be hell down there. There's only 2.50 meters of space, it's four degrees, there's no chair, no toilet."
Liobl said that he had been considering booking a trip aboard the Virgin Galactic spacecraft, which would cost him $250,000, but has rethought the trip "after the drama about the missing submarine, my whole pursuit of extremes is now in question..."
Rescuers scoured thousands of square miles in the remote North Atlantic since Monday, racing against time to find a missing submersible two days after it disappeared while taking wealthy tourists to see the wreckage of the Titanic in deep waters off Canada's coast.
The 21-foot Titan submersible has the capacity to stay underwater for 96 hours, according to its specifications - giving the five people aboard until early on Thursday before air runs out if the craft is still intact. One pilot and four passengers were inside the submersible early on Sunday when it lost communication with a ship on the surface about an hour and 45 minutes into its dive.
"I feel bad, I'm nervous, I have a sinking feeling in my stomach. I was incredibly lucky back then,” Liobl told Bild.
Reuters contributed to this report.