When the Magic School Bus takes a dive, Wanda discovers that one of Ms. Frizzle's ancestors was Redbeard the Pirate and a treasure map leads the class to a coral reef where they learn first hand that life there is risky. In The Magic School Bus gets swamped, the class learns that swampland is an important habitat and natural water filter. In the Magic School Bus goes to Mussel Beach, the class learns about life along a shore.