James Cameron almost died while filming “The Abyss.”

Cameron recalled filming scuba diving scenes with actors Ed Harris, Mary Elizabeth Mastrantonio and Michael Biehn for the 1989 film during a Q&A at the Beyond Fest film festival Wednesday.

“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,” Cameron told the audience, according to Variety. “[But] they weren’t watching me.”

To film the scenes, Cameron “wore heavy weights around [his] feet, no fins, a heavyweight belt around [his] waist” to move the cameras around nearly 30 feet underwater.

‘TITANIC’ DIRECTOR JAMES CAMERON REVEALS HE ‘KNEW THE TRUTH’ ABOUT SUBMARINE DISASTER

James Cameron revealed he almost drowned while filming “The Abyss” in 1989. (Gareth Cattermole/Getty Images for Disney)

“Everybody’s setting lights and nobody’s watching” as the director’s oxygen tank ran out of air.

“I’m trying to get [underwater director of photography] Al Giddings’ attention on the (public address). But Al had been involved in a diving accident, and he blew out both eardrums. So, he was deaf as a post,” Cameron shared. “And I’m wasting my last breath of air on an underwater PA system going, ‘Al … Al …,’ and he’s working away with his back to me.”

Cameron was able to remove his diving equipment as a safety diver attempted to help him out by sticking “a regulator in [his] mouth.” A regulator is used to deliver pressurized air to the diver from the tank, according to the Professional Association of Diving Instructors.

“The Abyss” won James Cameron an Oscar in 1990 for best visual effects. (Anthony Wallace/AFP via Getty Images)

“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,” he claimed. “And then I purged it again, and I took another deep breath … of water.

“At that point, it was almost checkout point and the safety divers are taught to hold you down so you don’t embolize and let your lungs over expand going up. But I knew what I was doing,” Cameron added. “And he wouldn’t let me go, and 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.”

James Cameron attends “The Abyss” screening during the 2023 Beyond Fest film festival Sept. 27. (Frazer Harrison/Getty Images)

“The Abyss” was awarded the Oscar for best visual effects at the 1990 Academy Awards. Cameron explained that the underwater scenes “certainly caught people’s attention at the time.”

“That scene made an impact and showed people what was possible, and I think it kicked in the door to the start of the CG explosion,” he said during the recent Q&A.

Cameron went on to direct other films that heavily relied on the depiction of water, including “Titanic” and “Avatar: Way of the Water.”