Whalefall ending: Jay survives, but never finds his father's remains

Jay Gardiner is swallowed by a sperm whale while searching for his late father’s remains.

He uses survival skills his father taught him to make an explosion inside the whale, then reaches the surface and is rescued by people on a nearby boat.

Jay survives with lasting injuries, including scars and the loss of his left hand; the whale dies from wounds inflicted by orcas, not from Jay’s escape.

Jay’s father, Mitt, had died by suicide after being diagnosed with terminal mesothelioma, and Jay never finds his father's remains.

On the boat, Jay finally reads the letter Mitt left him, but the letter's contents remain unknown because the film does not reveal its words.

Jay smiles as he reads, suggesting he is ready to face what his father wrote.

The film's rescue differs from the novel's: in Daniel Kraus’s book, the whale beaches and scientists help rescue Jay, and the story ends with his rescue.