Cotter Otter in Treasure Water

Cotter Otter is searching for treasure in the water when he comes across sea creatures different than himself. He doesn't want to play with them because they seem strange, and he doesn't think they can do the things he can. Cotter starts to learn what a real treasure is all about when the sea creatures have to come together in a scary situation, requiring quick thinking and the use of their unique talents if they are going to make it out in time.