Based on: The magic school bus series / by Joanna Cole and Bruce Degen.
Hi-fi stereo, Dolby BNR on linear tracks.
Closed-captioned for the hearing impaired.
A trip to the ocean becomes a search for the connection between Arnold's soggy shoe full of pond scum and Keesha's tuna fish sandwich. The bus shrinks and travels through the ocean food chain--getting eaten along the way!