A desperate search continues for the Titanic-bound submersible that went missing in waters about 900 miles east of Cape Cod, Massachusetts.
Five crew members are on board, and the 96-hour supply of oxygen on the vessel continues to shrink since its Sunday morning departure. Capt. Jamie Frederick of the U.S. Coast Guard said he would expect the submersible to run out of oxygen by Thursday morning if it remains intact.
The U.S. Coast Guard detected noises in the search area, but the vessel has yet to be found. A deep ocean salvage expert even called rescue efforts a "recovery operation," saying there's no way to get required equipment to the bottom before life-support runs out.
But two British sailors know what it's like to be down there — and survive.
A miracle story
The deepest underwater rescue ever achieved was that of Roger R. Chapman and Roger Mallinson, who were trapped aboard the Pisces III for 76 hours when it sank to 1,575 feet on Aug. 29, 1973, according to Guinness World Records. They were about 150 miles southeast of Cork, Ireland.
The pair had just 12 minutes of oxygen to spare when they were rescued.
Mallinson said news this week of the missing Titan sub, commissioned by OceanGate Expeditions, brought back feelings from the days he was trapped on a small vessel measuring 6 feet in diameter.
"You just rely on the thing being well-made," he told NBC News.
Through a series of interviews and retellings, publications over the years have told the tale of the miracle rescue.
Mallinson and Chapman's vessel crashed into the sea floor after the rope attaching it to the mothership above snapped.
"It was about 30 seconds until we hit. We turned the depth gauge off at 500 feet as it could have burst and got cushions and curled ourselves up to try and prevent injuries. We managed to find some white cloth to put in our mouths so we didn't bite our tongues off, too," Mallinson told BBC News in a 2013 interview.
The pair turned off all electrical so it was pitch black.
Mallinson and Chapman had just one sandwich and a lemonade — which they saved until the very end. They didn't have water supply, but licked condensation off the walls.
To conserve as much oxygen as possible, the two didn't talk or move after they phoned for help.
Noises heard in search area of missing Titanic submersible
Officials haven't been able to pinpoint where the noises came from as emergency oxygen is expected to run out by Thursday morning.
"We hardly spoke, just grabbing each other's hand and giving it a squeeze to show we were alright," Mallinson told the BBC. "It was very cold — we were wet through."
In a 2021 interview with Newsweek, author Stephen McGinty, who wrote about the rescue in his book The Dive, said salvage efforts faced a series of setbacks.
"The first sub to go down lost its lift line; the second sub down couldn't find them," McGinty said. "On a third trip they finally found Pisces III, but when they attempted to fix the lift line it locked on then fell out."
A team made repairs to a submersible on Sept. 1 and sent it down, where it was able to attach a rope to the sunken vessel. It wasn't until Mallinson and Chapman knew the rope was securely fastened that they had the sandwich and lemonade.
"It tasted like champagne to us," Chapman said, according to NPR.
Once on the surface, it took 30 minutes to open the vessel.
While the two were dehydrated, and Mallinson had mild hypothermia, they were in fairly good shape.
McGinty said a doctor who examined the pair called it "incredible."
Who are the people aboard the missing Titanic submersible?
The missing submersible carried five people, including a pilot, a French explorer, a British businessman and two members of a Pakistani family.
The way up for the pair had been rocky. Lift operations had to be stopped and restarted two times, with lots of swinging that was disorienting for Chapman and Mallinson. Chapman told the BBC that rescuers "thought we'd died when they looked at us, it had been so violent."
Each year on the anniversary of their legendary rescue, Mallinson would call Chapman at the exact moment they reached the surface, McGinty recounted.
Mallinson was 35 at the time of the incident, and Chapman was 28.
Chapman died of cancer in 2020, according to the BBC.
