The missing submarine, The Titan, developed by OceanGate and set to take several tycoons to visit the wreckage of the sunken Titanic in the North Atlantic, was supposed to have one more passenger.

This was another multi-millionaire who backed out after getting cold feet that the vessels were inadequately built and operated.

The OceanGate submarine headed for the wrecked Titanic, at 4,000 meters below sea level, went missing last Sunday with four days’ worth of oxygen supply.

Its five wealthy passengers paid $250,000 for a seat on the submersible, among them OceanGate’s founder, British millionaire Stockton Rush.

Chris Brown, a 61-year-old UK digital marketing tycoon, was supposed to also be onboard the now-missing vessel.

However, he decided to give up on the voyage because he thought the company operating it had been “cutting too many corners,” he told The New York Post, as cited by The Daily Wire.

Brown even paid a $10,000 deposit for the trip to the sunken Titantic, which he later received back, after deciding to skip the trip.

He was supposed to go together with Hamish Harding, another wealthy UK businessman.

Subsequently, Brown grew suspicious of the Titan submarine’s design. One of his biggest concerns was the vessel would be operated through a $40 video game controller.

The report notes video game controllers are now commonly used in running high-tech devices – including US military drones piloted through customized Xbox 360 controllers.

Yet, the British multi-millionaire was also worried the Titan sub was “haphazardly” assembled since it used “old scaffolding poles” for its ballast.

Brown asked for his deposit back after he became “less than convinced” that the vessel would be safe and capable of reaching the Titanic wreckage and coming back.

He said he was still harboring hopes for the survival of the five men on board the Titan, noting his friend Hamish wouldn’t be the type of person to panic in a dangerous situation.

On Tuesday afternoon, the US Coast Guard, which is helping in the search for the missing submersible, said it probably had oxygen for less than 40 hours.

There have been reports that rescuers heard “banging” noises underwater, but they are still being investigated.