Sailing from Lahaina, Maui to their homeport of Honolulu aboard their cargo hauling schooner, Tiny and his father, Slim, are attacked by a large humpback whale. She puts a hole in the bow of their ship, breaking one of the planks and damaging several others, causing water to pour into the small ship. Frantically, Tiny and Slim make emergency repairs to save their vessel from sinking, taking them along with it. Once temporary repairs are made and they save their ship, they return to Lahaina for permanent repairs.
While in Lahaina repairing their ship, Tiny feels the spirit of the whale calling him. This is 1856, and it had been reported that the whale has a harpoon in her side, the unsuccessful attempt by whalers to take her. Tiny knows he must go to her.
After repairs are made to their ship, father and son sail from Lahaina to where the whale had previously attacked them. There, Tiny, the powerful son of his English father and Polynesian mother, sets out in the ships dinghy to await the whale. She approaches Tiny warily, a calf by her side, but not before he dreams of being a whale himself, one harpooned when coming to the water's surface for the precious air necessary for his survival. The whale comes to Tiny wbile her calf awaits a distance off, but the struggle that follows is for the survival of both of them.