Don’t Be Prey is an adventure into one man’s fight to reclaim his life by taking on extraordinarily challenging channel crossings fraught with danger, the Oceans Seven. Featuring unforgettable characters, raw vulnerability, and the constant risk of sharks and jellyfish, it’s a gripping, uplifting journey of resilience, reinvention and what it really takes to survive.

The Challenge – Oceans Seven

The Oceans Seven is a marathon swimming challenge consisting of seven open water channel swims. It was devised in 2008 as the swimming equivalent of the Seven Summits mountaineering feat. It comprises the North Channel, the Cook Strait, the Molokaʻi Channel, the English Channel, the Catalina Channel, the Tsugaru Strait and the Strait of Gibraltar.

• Molokaʻi Channel (also known as the Kaiwi Channel): between Moloka’i and O’ahu, 45km/ 28mi

• English Channel: between England and France, 33.5km/21mi

• Catalina Channel: between Santa Catalina Island and Los Angeles, 32.3km/20mi

• North Channel: between Northern Ireland and Scotland, 34.5km /21.5mi 

• Cook Strait: between New Zealand’s North and South Islands, 22.5km /14mi

• Tsugaru Strait: between the Japanese islands of Honshu and Hokkaido, 19.5km/12mi

• Strait of Gibraltar: between Spain and Morocco, 14.4km/9mi

Characters

Mark Sowerby

Mark Sowerby’s life was upended in 2018 when a highly publicised short-selling attack on Blue Sky dismantled his reputation, identity, and self-belief. Turning to the ocean not for glory but for survival. Mark utilises marathon swimming as a mechanism to master fear and navigate the paralysis of prolonged uncertainty. Over the course of a decade, he attempts the Oceans Seven—a grueling odyssey through cold, darkness, and apex predators. By his final crossing, Mark’s journey transcends mere physical endurance, evolving into a profound reclamation of self, achieved only by surrendering control to a team he learns to trust implicitly.

Tim Denyer

Tim Denyer is an elite tactician whose uncompromising standards are inextricably linked to personal tragedy. A former channel swimmer, Tim bears the silent weight of having witnessed his own mentor perish in his arms during a crossing - a trauma that cemented his rigid, safety-first methodology. He offers empathy but withholds sympathy, operating within a binary philosophy where unchecked emotion is a precursor to fatal error. Viewing his own redemption through the lens of Mark’s survival, Tim pushes his athlete to the physiological brink, possessing the visceral knowledge of exactly what is required when the ocean turns unforgiving.

Heidi Sowerby

Heidi embodies the emotional gravity of the film, carrying the weight of her family while her husband confronts his existential demons at sea. Initially paralysed by the mortal risks inherent in Mark’s pursuit, she evolves from an anxious observer into an indispensable strategist, becoming the only voice capable of reaching him when he descends into a psychological void of suffering. Her arc mirrors Mark’s own transformation; moving from fear to agency, she eventually plunges into the freezing waters herself to guide him home.

Steven Munatones

As the creator of the Oceans Seven, Steven Munatones serves as the film’s philosophical conscience. A legendary figure in the sport, he contextualises Mark’s endeavour not merely as an athletic feat, but as a primal dialogue between "human power and Mother Nature". Steven lives by the ethos of the encyclopedia-bound explorers he idolised as a child, maintaining that comfort is the antithesis of a life well-lived. Having survived a catastrophic heart attack, he brings a poignant awareness of mortality to the narrative, reminding both the audience and Mark that the ultimate victory lies in refusing to become "prey" to life’s unpredictability.