James Cameron is opening up about the time he narrowly escaped death on the set of his 1989 film The Abyss.

While appearing at Beyond Fest in Los Angeles on a panel after a screening of The Abyss: Special Edition, the filmmaker revealed that he nearly didn’t survive to see the film actually hit the cinemas due to an underwater mishap, according to Variety.

“We had the ‘angels,’ which were the safety divers that were right there, and each one was assigned to one or two of the actors and just kept them in sight the whole time. [But] they weren’t watching me,” Cameron said of the precautions his team had in place for everyone’s safety while filming.

Cameron explained that the movie was shot “30 feet down” under water, which meant he had to wear “heavy weights” around his feet and waist to keep him submerged so he could move his camera around.

But one day on set, the unthinkable happened.

The director said he ran out of air at one point and tried to alert the underwater director of photography, Al Giddings, on the PA system.

His warnings fell on deaf ears though, as Cameron explained to the panel’s moderator, Jim Hemphill, that Giddings “had been involved in a diving accident and he blew out both eardrums”.

“I’m wasting my last breath of air on an underwater p.a. system going ‘Al… Al…’ and he’s working away with his back to me,” he added of the horrifying incident.

Cameron said that he was able to remove his gear and tried to resurface to get air, but that’s when another hiccup took place.

He said the “angels” began trying to help him, but wound up making matters worse by shoving a faulty breathing mask in his mouth.

“He sticks a regulator in my mouth that he didn’t check. It had been banging around the bottom of the tank for three weeks and had a rip through the diaphragm, so I purged carefully and took a deep breath… of water. And then I purged it again, and I took another deep breath… of water,” he said.

“At that point it was almost check-out point and the safety divers are taught to hold you down so you don’t embolise and let your lungs overexpand going up,” he continued.

Cameron said though he knew what he was doing as an experienced diver, but the safety diver wouldn’t let him go.

This left the Titanic filmmaker only one choice…to throw blows at the diving assistant.

“I had no way to tell him the regulator wasn’t working. So I punched him in the face and swam to the surface and therefore survived,” Cameron shared.

The Abyss was considered a box-office disappointment when it released, only earning around $9 million (£7.38 million) in the US. The film was initially met with mixed reviews, but later became a cult classic.