Clint Barlow has only grown a year since his appearance in Sea Pup but a lot seems to have happened to him. He went away for his first year in high school, and now, home for the first time, he's spouting out oceanography at length. With his future career all mapped out, he's set to do some investigation of his own now that he's back to his familiar sea coast territory. His old pet seal, Buster, has somehow escaped from the aquarium where the Barlows had left him, and gets back just in time to greet Clint. At 13 the boy is now apparently beyond any sort of frivolous adventure, and Buster is ready to settle down as his assistant. Even when Clint almost drowns it seems to be mostly as a demonstration of careless skin diving techniques. Under water subjects are popular for this age group, and this book may hold those with a strong interest in the field, but it's too one-sided to appeal to any one else.