Jeff Wadlow On Inventing ‘Entirely Different Cinematic Language’ For Shark Thriller ‘The Devil’s Mouth’

Jeff Wadlow on the set of 'The Devil's Mouth.'

Courtesy of Amazon Studios

Even fifty years after Steven Spielberg battled the elements to make Jaws, the challenges of shooting in water haven’t gotten any easier.

Simply put, "water and movie cameras do not get along well,” filmmaker Jeff Wadlow (Truth or Dare, Fantasy Island) recently told me over Zoom. “Add to that big lights running on electricity, and it’s a very tricky situation.”

The director unknowingly waded into the proverbial deep end when he entered a meeting with Lionsgate subsidiary eOne (acquired from Hasbro) in the hopes of slyly pitching them a G.I. Joe movie.

“They’re like, ‘We can’t talk about G.I. Joe, but we have this other script called The Devil’s Mouth we think you’d be perfect for,’” Wadlow remembered. “They said, ‘It’s a shark movie.’ I was like, ‘I don’t really want to do a shark movie. Jaws is one of my favorite movies of all time and I’m not sure there’s much more to be said in the sub-genre, even though I'm a massive fan of it.'"

He changed his mind after hearing the synopsis—a “claustrophobic horror movie that takes place in a freshwater cave system"—and reading the screenplay by Aja Gabel and Myung Joh Wesner, which had made the 2019 Black List under the title Apex.

“It was this complex, nuanced depiction of a very complicated female friendship,” said Wadlow, who had a gut feeling the project would be to actors what chum is to sharks. “And I was right," he added, "because we got Kathryn Newton and Lana Condor.”

The Devil’s Mouth centers on a group of friends vacationing in Thailand—Sara (Newton), Max (Condor), Nico Hiraga (James), Gavin Casalegno (Greg), Tommi Rose (Adrienne)—who suddenly find themselves stalked by a territorial predator of the deep within a labyrinthine cave system from which there is no escape.

But first, Wadlow had to try and out-swim the influence of the original summer blockbuster as best he could.

“Jaws looms large, it casts quite a shadow,” he conceded. "I just tried to think about it as a film fan. If I was a fan of Jaws, which I am, what would I want from a shark movie as an evolution in that sub-genre?”

To that end, the director considered shark-based survival thriller contemporaries like Jaume Collet-Serra’s The Shallows, Johannes Roberts’ 47 Meters Down, and Xavier Gens’ Under Paris; going so far as to sit down with Gens over coffee in order to pick his brain.

“When I finish making a movie, I now know how to make that movie, and it’s very frustrating,” Wadlow said. “It’s like, ‘I wish I had all those lessons before I started.’ So, I often will try to contact filmmakers who recently made a similar film to the one I’m about to make and say, ‘Hey, what lessons did you learn? Can you offer any wisdom that I can maybe benefit from?’"

Despite the guidance and reassurance from a colleague, nothing could have fully prepared him for the watery plunge. “The whole movie takes place in water,” stressed Wadlow. “I mean, for 85 percent of the film, our characters are actively swimming. I’m not just talking about near water or on a boat. They are in the water, up to their chins for 85 percent of the movie.”

That immediately ruled out a number of reliable tools in a moviemaker’s arsenal: dollies, Steadicam, and handheld shots.

“You can’t do a handheld shot when people are swimming, even if the operator can stand, because you have to put the camera in a HydroFlex to protect it, and a HydroFlex weighs like 120 pounds,” Wadlow continued. “We had to invent an entirely different cinematic language out of pure necessity … What we did was truly insane."

For example, he often ran four cameras at a time, “not [because] I was getting four shots for that one little scene,” he noted. “I would actually have the actors moving through four different masters as they were swimming. Then I would lens up and come in for my coverage. But I would try to take a scene you would normally break down into chunks and just shoot it almost like a play because I had limited time in the water and had to make the most of every setup.”

Moreover, he made a point to be in the water with his cast and camera operators as much as possible: "Every day, my assistant would laminate my shot list and hand me a laminated [script page], so I could get in the water and still read what the plan was without the paper falling apart.”

Before trapping the characters in a claustrophobic location with very little hope of rescue, Wadlow hoped to cleverly lure viewers into a false sense of security by showcasing the wide-open natural beauty of Thailand.

“What I suggested to the team was, ‘Let’s start really big [with large] wide shots and drone shots,’" he shared. "'Let’s sell the trip. People should be excited to be here with our characters and not think this trip is a bad idea.’"

While the production did shoot at an actual freshwater cave for a number of establishing shots, most of the interior, cave-based action was filmed on soundstage tanks in Bangkok for obvious reasons.

“We built one big cave set,” Wadlow said. “It was 120 feet long, 70 feet wide, and flooded with five feet of water.”

He continued: “There are 13 caves scripted in the movie. I had two sets, so I would just bounce between them and figure out which cave I could shoot on which set. Fortunately, Alec Hammond, the production designer, is a is a mad scientist. He came up with these plans where we would move walls, change a rock, have a certain light, or something that would give it a different feel. There are scenes in the movie where the actors swim out of the cave and right back into the same exact set. You don’t know it, but that’s what they’re doing."

As the danger intensifies, small cracks begin to form among the group, especially between the timid Sara and domineering Max. The unimaginable stress put on their longtime friendship by the adrenaline-pumping fight-or-flight situation effectively becomes the emotional crux of the movie. Prior to filming, however, the two actresses wondered whether they might be better-suited in the other’s role.

“They both said to me, ‘You know, typically I would play the other character,’ and I think that’s what made the casting so interesting,” Wadlow said. “Kathryn had to find something inside of herself that was a little bit different than what she normally plays to bring Sara to life, and Lana had to do the same thing for Max … The casting was unconventional, but I think really helped the story."

It also helped that the entire cast was gung-ho to bring his vision to life.

“They did all their own stunts,” he concluded. "They were being jerked around on winches, they were doing breath holds, they were in the water for hours and hours a day—and they never complained. I just feel really fortunate, because if you had any of that cliche diva attitude you sometimes hear about with actors of all different levels, the movie wouldn’t have worked. If Lana and Kathryn had some sort of feud about who gets better treatment, I couldn’t have made this movie. The fact that everyone was on board, excited to be there, and down for the adventure made it possible.”

The Devil’s Mouth is now streaming on Prime Video