Beautiful quality pictures- and plenty of them!
It has a map of the world, so you can orientate yourself. It tells you a little bit on how to behave around pelagic species and mainly what and where you can see them. It emcompasses around "The Caribbean and Atlantic", "Red Sea and Indian Ocean", "Indo-Pacific", and "Greater Pacific". It also includes essential information- climate, best time to go and how to get there, water temp, visibility, quality of corals and marine life, depth of dives etc. It also has weblinks and further info and reading.
Found this book useful- but I am more blown away by the Shark Watchers Handbook- felt that that book also has given me information about these pelagic species (despite it being a shark watchers book).