Pims parents tell him to throw his goldfish Harry into the canal when they go on a holiday.
Feeling sad, Pim leaves for their holiday home at the sea, where hell be competing in a competition. A competition? Harry thinks. Count me in!
Harry is determined to win the competition and takes off on a long swimming race.
Along the way he meets special animals and he experiences much more than he did in his bowl at home! At the end of the journey Harry is the quickest swimmer, but is the competition indeed a swimming competition?