I was disappointed in this book. The authors have done a lot of diving, but world-class dives that they haven't visited or don't like are omitted and some of their comments, notably about Nitrox diving, are very controversial. I'm an underwater photographer and a medical doctor, so I have a little experience in these areas: a book that misses out the Sudanese Red Sea and Bikini Atoll and yet claims to be a guide to tropical diving is incomplete, at best. The authors say "if you really wanted to know about the English Channel, we didn't do it. It wasn't on anyone's list"; maybe, but the Californian Channel Islands, South Africa, New Zealand, Cocos and Malpelo are cool water locations on many divers' wish-lists (and there are some who are even interested in Scapa Flow!).
What's in the book is very good, but to go Diving the World you need to look elsewere. I recommend Monty Halls' "Dive" and Jack Jackson's "Diving with Sharks" as good places to start.