John and Catherine McCormick relocate from Vancouver, Canada to the coast of British Columbia, where sailing enthusiast John teaches his 16-year-old son Angus and 9-year-old son Silas basic seamanship and outdoor survival skills. Angus has rescued a stray Golden Labrador that he names Yellow, and considers Yellow to be his best friend, though John and Catherine aren't so sure Angus is responsible enough to care for Yellow. But Angus talks them into letting him keep Yellow. One day while John, Angus, and Yellow are out on the ocean in their boat, just the three of them, they drift right into a storm with hurricane-force winds, and a huge wave swallows the boat. John is found almost right away and taken to a hospital, but Angus and Yellow are nowhere to be found, because they are in the lifeboat that they had with them. The lifeboat drifts Angus and Yellow to nearby land, a strange place that seems far from any civilization. Angus and Yellow's abilities to survive in the wild are put to the test. As Angus and Yellow fend off wild animals, build a shelter, and signal for help, John and Catherine work with the Coast Guard in a desperate search for Angus and Yellow.