Follow the Whales(1973)
The Hydronauts Meet the Otter People
(The second book in the Hydronauts series)
A novel by Carl L Biemiller
In this sequel to The Hydronauts, the four hydronauts receive orders to search out the men-fish who follow the whale herds to see if they should be allowed to live.
Used availability for Carl L Biemiller's Follow the Whales
1973 : USA Hardback