The ocean is Earth’s ultimate hostile environment. While cinema frequently populates its depths with prehistoric sharks and mythical leviathans, the most terrifying cinematic abyss requires no embellishment. It merely demands a faithful recreation of human vulnerability against the crushing weight of millions of tons of seawater. Dangerous Waters (2025), the harrowing adaptation of Stephen McGinty’s exhaustive non-fiction book The Dive, achieves exactly this. Stripping away the bombast typical of the survival thriller genre, it delivers an agonizing, masterfully restrained procedural that traces the 1973 rescue of the Pisces III submersible.
In executing this claustrophobic nightmare, the film not only honours the deepest successful submarine rescue in history but also forces audiences to confront the terrifying limits of human endurance. It is a cinematic experience that leaves you gasping for air, both figuratively and literally.
The Anatomy of a 1973 Nightmare
To understand the triumph of Dangerous Waters, one must first understand the chilling reality of its source material. On August 29, 1973, two British submariners - former Royal Navy officer Roger Chapman, 28, and engineer Roger Mallinson, 35 - were laying a transatlantic telephone cable in the Celtic Sea, roughly 150 miles off the coast of Ireland. Their vessel, the Pisces III, was a commercial submersible designed for utilitarian deep-sea labour, not comfort.
During a routine procedure to bring the submersible back to its surface command ship, the Vickers Voyager, a towline fouled the aft sphere. The hatch ripped completely off, allowing tons of water to flood the rear compartment. Instantly inverted by the tremendous weight of the influx, the Pisces III plummeted 1,575 feet (480 metres) to the seabed. In the film’s first act, this catastrophic descent is rendered with sickening realism. There is no swelling orchestral score, only the shrieking of buckling steel and the violent shuddering of the six-foot-diameter sphere as the men are thrown into darkness.
What follows is an excruciating waiting game. Chapman and Mallinson survived the initial impact but faced an even grimmer reality: they were trapped under 1,575 feet of water, enclosed in a steel ball, with an initial estimate of 72 hours of life support. They would ultimately be trapped for 84 hours and 30 minutes, surviving on rigorously conserved oxygen, a single can of lemonade, and one cheese and chutney sandwich.
Edward Hemming’s Claustrophobic Screenplay
If the evolution of British historical cinema has taught us anything, it is that less is often more. Screenwriter Edward Hemming (best known for his meticulous work on The Crown) understood that the tension of the Pisces III incident did not require fictional dramatization. Adapted directly from McGinty’s meticulously researched account, Hemming’s screenplay refuses the easy temptations of Hollywood melodrama.
Instead, the dialogue is sparse, dictated by the very real physiological need to conserve oxygen. The characters lie in near-absolute darkness, wrapped in whatever they can find to stave off the freezing temperatures. They cannot speak frequently. They cannot move. They simply have to exist and wait for the carbon dioxide scrubbers to do their work. The film brilliantly captures the psychological toll of this enforced immobility. Their whispered prayers and brief exchanges syncopate with the relentless dripping of condensation from the pipes - a constant, rhythmic reminder of the ocean trying to claim them.
Hemming successfully juxtaposes this terrifying, frozen stillness at the bottom of the sea with the frantic, chaotic surface operation. The audience is frequently ripped from the silent tomb of the Pisces III and thrust onto the deck of the Vickers Voyager, where a multinational rescue effort battles against time, heavy seas, and a string of mechanical failures.
The Mechanics of Rescue on Film
The logistical nightmare of a 1970s deep-sea rescue is where Dangerous Waters truly flexes its procedural muscles. Mark Gordon Pictures, the production company behind the adaptation, has clearly invested heavily in the practical realism of the operation. The rescue was not achieved by a solitary hero, but by a sprawling, international team utilizing experimental and temperamental technology.
The film painstakingly documents the deployment of other submersibles to locate and attach a lifting line to the stricken Pisces III. We watch the Pisces II submersible forced to surface due to a leak. We see the Pisces V finally locate the men but prove unable to lift them. Ultimately, the tension hinges on the arrival of the United States Navy’s CURV III (Cable-controlled Undersea Recovery Vehicle), an unmanned remotely operated vehicle which had to be flown in and assembled under immense pressure.
Directorially, the handling of these rescue sequences avoids triumph. Every setback is felt deeply because the film has already established the suffocating reality of the two men below. When the lifting line is finally attached, the slow, agonizing haul to the surface is fraught with the constant threat of the cable snapping. The technical jargon is not dumbed down for the audience; rather, it is used to immerse us in the professionalism of the crews who knew that a single miscalculation meant two men would slowly asphyxiate in the dark.
Sound Design and the Echoes of the Abyss
A film set largely inside a six-foot steel sphere relies entirely on sensory details to convey its horror. Dangerous Waters represents a masterclass in how sound design shapes our psychological response to film. The sensory deprivation of the abyss becomes the film’s most potent weapon.
Because Chapman and Mallinson are plunged into pitch blackness for large portions of the film to conserve battery power, the audience is forced to rely on audio cues. The ping of the surface sonar trying to locate them becomes a literal lifeline - a sound that brings desperate hope, but also highlights their extreme isolation. The creaking and groaning of the pressure hull under the weight of 1,575 feet of water is a constant, terrifying character in the room. Even the sound of the men's own breathing is weaponized against the audience, as the buildup of carbon dioxide makes every inhalation sound laboured and toxic.
When the rescue submersibles finally clank against the exterior of the Pisces III, the metallic thud reverberates through the cinema like a thunderclap. It is an extraordinary feat of audio engineering that makes the audience feel the oppressive weight of the Celtic Sea pressing in from all sides.
A Submarine Genre Resurfaced
Dangerous Waters enters a specific subgenre of cinema - the submarine thriller - that has historically yielded powerful results. Films like Das Boot and Kursk have long played on our innate fear of enclosed spaces and drowning. However, Dangerous Waters operates on a different frequency. It is not a war film, nor is it a geopolitical tragedy. It is a story of blue-collar workers engaged in routine commercial labour who suddenly find themselves at the mercy of the elements.
In 2025, a film about a deep-sea submersible disaster inevitably carries heavy cultural baggage. It is impossible to watch Dangerous Waters without the shadow of recent, tragic billionaire submarine expeditions looming over the narrative. Yet, the film respectfully avoids drawing explicit parallels, allowing the 1973 context to stand on its own. The contrast, however, is palpable. Chapman and Mallinson were not tourists seeking a thrill; they were engineers doing a job, and the multinational rescue effort mobilized to save them was a testament to the sanctity of human life.
The film captures the sheer, unadulterated grit required to survive. When the Pisces III was finally pulled to the surface on September 1, 1973, and the hatch was painfully wrenched open, the reality of their survival was almost mathematically impossible. As Roger Mallinson later famously revealed, when they were finally extracted after 84 and a half hours, they had a mere 12 minutes of oxygen remaining.
Cinema’s New Abyss
Dangerous Waters succeeds because it does not attempt to conquer the ocean; it merely documents the terror of surviving it. It is a film that relies on the terrifying mathematics of oxygen depletion and pressure, anchored by a screenplay that respects the stoicism of the men who endured it.
Edward Hemming and the production team have crafted a work that feels less like a traditional Hollywood thriller and more like a high-stakes historical document. It is dense, factual, and relentlessly tense. By the time the credits roll, the audience is left physically exhausted, deeply appreciative of the surface world, and acutely aware of the dark, silent abyss that waits just off the continental shelf. In Dangerous Waters, the true monster is the ocean itself - and it has never looked more terrifying.
