Manatee

It is a fantasy adventure novel especially for young readers. The setting is a small island off the coast of Venezuela. It's a story of a baby boy, attached to a rubber raft on a yacht sailing from the island of Trinidad who gets washed overboard in a storm and found by a nefarious scientist, the inventor of an artificial gill. He uses the baby as a guinea pig and successfully implants gills under his arms. When a tidal wave washes over the island, where the scientist and his assistant have their laboratory, they are drowned and the baby is washed out to sea. A female dolphin, that has just lost her newborn calf, finds the baby and adopts him as her own and names him Manatee. She raises him to be part of the dolphin group and teaches him to be like a dolphin. He learns to swim like them, develops amazing strength, and learns their language. He is twelve years old when he discovers his human origin which opens up a whole new world of adventure for Manatee.