Kaimana and his father, Slim, are sailing their cargo hauler, Island Lady, from Lahaina, Maui to Honolulu when they are attacked by a humpback whale that holes their small ship, causing water to pour into her. Frantically, Slim and Kaimana make emergency repairs to save their vessel from sinking and taking them down with her. Once temporary repairs are made and they save their ship, they return to Lahaina for permanent repairs.

While in Lahaina repairing Island Lady, Kaimana feels the spirit of the whale calling him. This is 1828, and it has been reported that the whale has a harpoon in her side, an unsuccessful attempt by whalers to take her. Kaimana knows he must go to her, even though she is the whale who had attacked them. His father consents, even though he fears for his son's safety, and when their ship is repaired, they sail to where the whale had first attacked them.

There, Kaimana, the powerful son of his English father and Polynesian mother, sets out in their ship's dinghy to await the whale. He waits for days and nights before the whale comes to him for help, but not before he dreams of being a whale himself. One harpooned when coming to the water's surface for the precious air he needed to survive.