Sawyer Nelson, a lonely 11-year-old boy, has fallen behind in school since being abandoned by his father five years earlier. His only friend is his cousin Kyle, a champion swimmer who hopes to compete in the Olympics. Kyle leaves to spend time in the army.
Three years after saving Winter (dolphin), Sawyer, now aged fourteen, gets a chance for a scholarship to the elite Sea Education Association program, which involves three months at sea doing marine mammal research, after impressing his cousin Kyle's advisor Dr. Miguel Arroyo when champion surfer Bethany Hamilton swims with him and Winter. Sawyer is reluctant to go because he is concerned about leaving Winter.