This book will provide a basic scientific framework for tropical divers who want to be more than just diving tourists. It covers the different reef zones and the interaction between them, provides an overview of the different animal families, explains the food chain and the interaction between plant and animal life, and describes the differences in feeding behavior between grazers, bottom feeders, nighttime hunters, and daytime hunters. All in a compact, clear format that can be easily polished off in a 4 hour plane ride. My only criticism is that this book, like most of the Pisces guides, is no more substantial than an issue of a good magazine.