How They Shot the Breathable Fluid Scenes in ‘The Abyss’

If you think it's CGI ... don't hold your breath. Or, wait, maybe do.
Ed Harris The Abyss Breathable Fluid

Welcome to How’d They Do That? — a monthly column that unpacks moments of movie magic and celebrates the technical wizards who pulled them off. This entry explains how they shot the breathing fluid scenes in James Cameron’s deep-sea action sci-fi movie The Abyss.


Let’s get one thing straight: there are blank checks, and then there’s The Abyss. Hot off the commercial and critical successes of 1984’s The Terminator and 1986’s Aliens, director James Cameron and his then-wife/producing partner Gale Anne Hurd settled on their next project.

The idea had been wriggling around in Cameron’s creative noggin since scuba diving stole his heart as a teen. The movie would tell of a group of blue-collar workers, stationed on Deep Core, an experimental underwater drilling platform near the Cayman Trough. When a US submarine sinks into the titular abyss after an encounter with a mysterious foreign object, the civilians, allied with a Navy SEAL team, rush to salvage the wreck before the Soviets. In the process, they find themselves at the heart of humanity’s intergalactic Judgment Day.

The breathing fluid scenes in The Abyss

When the SEAL team first arrives in The Abyss, the merge is not all that harmonious. These military folk bark orders, reek of elitism, and possess fancy, cutting-edge playthings. “What is that stuff?” asks Hippy (Todd Graff), the rig’s resident conspiracy theorist. Circling the outskirts of the station’s loading bay, Hippy’s eyes lock on a small container of unnaturally pink liquid. “Fluid breathing system,” responds US Navy SEAL Ensign Monk (Adam Nelson), “We just got them. You use it when you go really deep.”

Hippy asks what we’re all thinking: how deep, exactly? “It’s classified,” Monk responds curtly. “Anyway, you breathe liquid so you can’t get compressed; the pressure doesn’t get you.” Leaning in skeptically, Catfish (Leo Burmester) asks for clarification: “You mean you got liquid in your lungs?”

Not just any liquid. “Oxygenated perfluorocarbon emulsion,” Monk clarifies.

Sensing doubt, Monk upturns a nearby wire cage, spilling metallic bolts across the table. He snatches Hippy’s white pet rat off his shoulder, submerging the creature. Using the wire cage as an improvised lid Monk traps the squirming rodent beneath the surface. To Hippy and Catfish’s amazement, after some struggling, the rat breathes the fluid.

In the third act of the movie, wouldn’t you know it, the rig’s foreman, Bud Brigman (Ed Harris), has to go deep. Classified deep. Bottom of the Cayman Trough deep. And so, with an understandable degree of fear in his eyes, Brigman suits up.

He gives the rat a kiss in solidarity and affixes the helmet, which slowly fills with the strange pink liquid. With some encouragement, he takes a breath of the stuff and lurches backward, shocked and acclimatizing to the bizarre feeling. With wild eyes, his shock is palpable: he’s breathing liquid.


How’d they do that?

So what’s going on here? In The Abyss, we see what looks like a rat breathing in fluid and living to tell the tale. And here’s leading man Ed Harris, appearing to do the same for a good chunk of the movie’s third act. What’s Cameron up to, exactly?

Long story short:

The rat demonstration scene in The Abyss was unsimulated and used real-life oxygenated breathing fluid. Ed Harris, however, was tasked with pretending to breathe in his water-filled helmet. This was especially challenging during underwater shots, of which there were many.

Long story long:

Before we dive into the deep end, we ought to acknowledge our primary source: Ed W. Marsh’s Under Pressure: Making ‘The Abyss,’ which is inarguably the best behind-the-scenes documentary ever made. The documentary begins with our intrepid director emerging from the inky darkness in a wetsuit and illuminated helmet. “I’m James Cameron,” the figure states between the wheezes and clicks of his respirator. “And I want to take you into a world of cold, darkness, and unrelenting pressure: the movie business.”

Committed, hell or high water, to shoot as much “real-for-real” as possible, the production of The Abyss was inundated with complications. Underwater sequences for the movie were shot in two hastily constructed tanks in an abandoned nuclear power plant in Gaffney, South Carolina. At the time, it was the largest underwater set ever constructed. And when you hear about the laundry list of complications, it’s easy to understand why no one had done anything like this before.

This is a shoot where things started with chemical burns (from the chlorine in the tanks) and then got worse. Despite the whole situation being a hell of his own making, no one was more aware of the hardships of the shoot than Cameron himself. “Water basically just adds a level of difficulty to any human endeavor, no matter what it is,” Cameron states blankly in Under Pressure, like a shell-shocked war veteran. Keep in mind, per an estimate in Starlog magazine issue #146, forty percent of all the live-action principal photography in The Abyss takes place underwater.

You would think that on a shoot like The Abyss where water was not just an inconvenience, but potentially life-threatening, the last thing you’d want to do is actively court death by bringing breathing fluid into the mix. But you would, of course, be wrong. This is James Cameron we’re talking about.

“I was a little apprehensive about sticking this rat into this water,” remarks Adam Nelson in the documentary, “for fear of what everybody else would think: that it would end up killing this rat.” The fluid you see on-screen is, in fact, real oxygenated perfluorocarbon fluid that allows mammals to appear to “breath water.”

Dr. Johannes Kylstra and Dr. Peter Bennet of Duke University pioneered the technique, and consulted with Cameron, providing detailed instructions for its use. Per the Starlog article: Cameron’s initial inspiration for The Abyss traces back to a lecture he attended in high school where Francis J. Falejczyk, the first human being to breathe oxygenated fluid, spoke about the technology being developed at Duke.

Supposedly, the only purpose for the cuts in the sequence was to avoid showing the rats defecating from panic. In total, the crew shot the scene five times with five different rats. Aftercare included holding the rats upside down to drain their lungs of fluid coupled with a vet visit. None of these efforts assuaged the concerns of the English censors, who cut the scene for UK distribution.

As Van Ling, Cameron’s creative/technical research assistant notes in a blistering op-ed in the Los Angeles Times, the point of the scene “was to see the rat survive, so rest assured that we didn’t spend the time and effort consulting with various experts and the $400 a gallon of real liquid perfluorocarbon just to kill the poor thing … we did the scene for real … and the rat survived the scene, for real.”

As a New York Times piece notes, Falejczyk, the human perfluorocarbon test subject, nearly died. And movie stars are less expendable than rats. Harris was the only actor in The Abyss who had to endure the breathing fluid. In one of the more memorable scenes of the Deep Suit, his character, Bud Brigman, stares intently into the eyes of his estranged wife as the suit’s helmet steadily fills with pink-toned fluid.

In reality, just out of frame, the crew simply pumped colored water into Harris’ helmet. It was up to Harris to go through the motions of panic and amazement that he could, in fact, breathe underwater. Which, to reiterate: he could not. Like Bud, Harris wore custom contact lenses in order to see inside a fluid-filled helmet.

“Because I was constantly exposed to the water, and there was a high amount of chlorine … it wouldn’t take more than five minutes down there before my eyes would start stinging,” Harris recalls in Under Pressure. “I would try to stay down there as long as possible because the more we could shoot … the less time I’d have to be down there.”

For the scenes in The Abyss outside of the oil rig, after Bud has descended through the moon pool, Harris wore a special helmet rigged with a tinted faceplate that could flip up. This accomplished a dual purpose: it allowed Harris to fill his helmet up with water, and it gave Harris easy access to a regulator between takes.

“We did a lot of safety drilling and rehearsals in shallow water,” recalls Cameron in the documentary. “At no point was [Ed] really afraid for his safety. Other than the fact that we really had to be very rigorous in the way we did everything.”

To simulate the moment in The Abyss where Bud freefalls rapidly underwater down an abyssal trench, Harris was towed sideways across a fake rock wall. This was to avoid the need for Harris to equalize during a descent. (Equalizing is an unglamorous process that isn’t great for close-ups.)

This was, to put it lightly, a terrifying situation for Harris, who recalls in Under Pressure: “Holding your breath, you can’t see, you can’t move, you’re forty-five feet underwater, you don’t have any air supply of your own [and] they’re going to drag you two hundred feet across the bottom of this tank while you’re acting.”

After a successful test with Charlie Arneson, one of Harris’ stunt doubles, the actor strapped himself into the tow-rig. Between a rehearsal and one of the first takes, Terry Kerby, one of Harris’ safety divers, got tangled in a cable. When Harris signaled that he was out of oxygen, the rig came to a halt. Harris clung to the wall awaiting his air supply. But no air supply came.

“I was hanging there, out of breath with no air, thinking: this is great,” recalls Harris in the doc. Another crewmember swam over to Harris and improperly inserted his extra regulator into Harris’ mouth, causing the actor to inhale a lungful of half-air-half-water. “For a split second I really thought I was a goner,” he continues.

Then, Al Giddings, the underwater director of photography, ripped the reg out and gave Harris his own extra air supply, correctly. In the documentary, the actor recalls bursting into tears during his drive home that night. “There was a part of me that was really disappointed in myself for not being able to do this thing. And there was also a part of me that just didn’t know what to do … I really thought I was going to die for a second and it also pissed me off that I was afraid of that.”

“Ed was probably the ultimate trouper in the world,” Cameron remarks, once again in Under Pressure, his eyes jet-black, not unlike a shark’s. “If he wasn’t before The Abyss he certainly was afterward.”

What’s the precedent for those scenes in The Abyss?

In the aforementioned Starlog article, producer Gale Anne Hurd underlines that, in more ways than one, The Abyss was new territory. “There have been many firsts in this production,” agrees director of photography Mikael Salomon. “It’s far and away the most technically innovative and demanding shoot I’ve ever done. A real challenge.”

As far as the scene where a very real rat breathes in very real oxygenated perfluorocarbon? Much like The Abyss’ seven-and-a-half-million gallon tank, there simply is no cinematic precedent for the use of breathing fluid. But actors nearly drowning in scuba-related situations? That’s another story.

Only one commercial film contains nearly as much scuba-action as The Abyss. And that distinction belongs to Thunderball. The 1965 James Bond movie features a truly ridiculous amount of real underwater action (around twenty-five percent of the screen time). And, per the “James Bond in the Bahamas” featurette on the Casino Royale Blu-ray, one underwater scene nearly drowned a stunt double.

In the movie, there is a scene where a SPECTRE agent severs another man’s oxygen supply underwater on a jet plane. Unfortunately, the stunt double accidentally disconnected both the prop and the real oxygen line of the other double. The key difference here, which Cameron gets to claim as a first, was denying his actor oxygen in a scuba situation on purpose.

So yeah, Ed Harris had it rough. But think of it this way: at least he didn’t have to swim with fifteen real-life sharks, as Connery did for Thunderball. No one tell James Cameron about sharks.

Meg Shields: Meg Shields is the humble farm boy of your dreams and a senior contributor at Film School Rejects. She currently runs three columns at FSR: The Queue, How'd They Do That?, and Horrorscope. She is also a curator for One Perfect Shot and a freelance writer for hire. Meg can be found screaming about John Boorman's 'Excalibur' on Twitter here: @TheWorstNun. (She/Her).