A man who survived being stuck in a submersible for 3 days said it felt like there wasn't even 'one atom of hope' left for him as time dragged on

• Roger Mallinson survived being stuck in a submersible for three days in September 1973.
• Mallinson told Newsweek about the mental toll for those aboard the missing submersible.

A man who survived after being stuck in a submersible for three days in 1973 spoke to Newsweek about the immense mental strain he went through when plunged into a similar life-and-death scenario.

"They will have absolutely not one atom of hope," said Roger Mallinson of the people in the missing Titan tourist submersible.

Mallinson, a former British Royal Navy pilot, survived the world's deepest underwater rescue in September 1973, according to the Guinness World Records. He was with his late co-pilot, Roger Chapman, when a broken hatch sent their submersible, the Pisces III, plummeting 1,575 feet below sea level. The two men had been on a regular dive to lay transatlantic telephone cables on the seabed, just 150 miles off the coast of Ireland.

There was a happy ending to Mallinson's story: He and Chapman were rescued from the Pisces III on September 1, 1973, with just 12 minutes of oxygen left, per the BBC.

"It took 84 hours to rescue us," Mallinson told Sky News. "We didn't have enough food. We didn't have enough oxygen."

"We just had to really be rationing everything and look after each other," he added.

Five passengers, including the submersible's maker Stockton Rush and British billionaire Hamish Harding, are currently lost in the missing submersible.

The US Coast Guard said in a statement on Wednesday that rescue efforts are ongoing.

Search teams have been racing against time to locate the missing submersible, which could run out of oxygen by Thursday afternoon.

"If I could say anything to them, it would be to stay warm and keep hoping," Mallinson told Newsweek.

"If you have a hammer, it would be great to knock on the sphere, make some noise. It will transmit a hell of a long way. They are all listening for it," he said.

The US Coast Guard said in a tweet on Wednesday that they have detected underwater noises in the search area and have shared sound recordings with the US Navy "for analysis to help guide future search efforts."