Whalefall

Leave it to the marine biologists to determine the anatomical accuracy of Whalefall, an oddball thriller that might make you lose your appetite.

Requiring a significant suspension of disbelief that’s rarely earned, this aquatic survival saga features striking visuals both above and below the surface, yet from a narrative standpoint, it’s not as filling.

Be warned that despite pitting man against beast, this is not a conventional horror exercise, although it has elements both frightening and disgusting — especially the latter.

It follows Jay (Austin Abrams), the son of California boat captain Mitt (Josh Brolin), who recently took his own life in the ocean following an illness, prompting Jay to relocate with his mother (Elisabeth Shue) to Iowa.

Jay remains burdened by unresolved grief that has spiraled into a debilitating obsession with seeking closure and catharsis. He impulsively heads back to the coast by himself to dive in search of Mitt’s remains — where he comes into contact with a massive sperm whale, eventually being trapped inside its mouth.

A series of flashbacks provides insight into a volatile relationship where Mitt’s passion and overbearing insistence on Jay following in his footsteps has made Jay desperate to win his posthumous approval.

As with other mammals, once food reaches a certain point in the whale’s digestive tract, there’s only one way out, and it’s not how you came in. With that reality sinking in, Jay’s journey becomes sort of an existential struggle.

The film benefits from meticulously detailed creature effects. Jay’s first encounter with the whale is harrowing if hardly convincing, as the intended entrée after a giant-squid appetizer. Forced to act by himself in many of his scenes, Abrams (Resident Evil) admirably puts himself through the physical and psychological wringer.

The screenplay by director Brian Duffield (No One Will Save You) and novelist Daniel Kraus, upon whose book the film is based, carefully parses out contextual details in a calculated attempt to justify Jay’s reckless decisions.

Short on traditional thrills, the biggest challenge in translating this material from page to screen might be persuading moviegoers to take it seriously. As it becomes darker and weirder, it struggles to raise the emotional stakes as intended.

Regardless, the film might break new ground in its intimate and graphic depiction of a whale’s gastrointestinal system. So depending on your tastes, at least Whalefall has guts.

Rated PG-13, 106 minutes.