Amelia Bedelia and her mother share a summer vacation home at the shore with her aunt Mary (her mother's sister) and her cousin Jason, who has a wicked sense of adventure and a nose for trouble. With a local girl named Pearl as guide, the cousins build sand castles, swim and body surf, and learn how to sail. As much fun as their nautical adventures are, the lives of this trio get way more exciting when they stumble upon pirates!