Together with their unexpected guest, Lenny the Lifeguard, Ms. Frizzle and her class take a trip into the ocean in their ever-evolving magical school bus. The group visits the continental shelf, the ocean floor, and a coral reef, and ends their journey with a "school bus surfboard" ride back to the beach. Cartoon-like illustrations depict the expedition while facts about the sights shown are interspersed with the class's humorous repartee. Earlier books in the series published by Scholastic include Magic School Bus at the Waterworks (1986); [...] Inside the Earth (1987); [...] Inside the Human Body (1989); and [...] Lost in the Solar System (1990). (Ages 6-10)