Each title in this series is a bestseller. But perhaps that's not surprising. The books take a unique approach for divers, combining the best aspects of a great dive-only guide and mixing them with the travel information you need. The focus is definitely on things to see below the waves, with top dive and snorkel sites described in detail and ranked for visual excellence. Sites include shipwrecks, coral walls and reefs, blue holes, underwater trails and even sunken planes. An ability rating helps you determine the right sites for your skill level. Every spot is shown on island maps.

What makes the books unique is the amount of information for landlubbers (or divers that have to rest for the day), including local museums, jeep excursions, historic forts and more. The authors -- both experienced divers -- provide a selection of diver-friendly resorts, hotels and live-aboards that offer tank refills, boat rentals, on-site certification, equipment rentals or night dives. Restaurants are also given. An extensive "Facts" section at the end of each area profile gives easy-to-read travel info -- climate, clothing, vaccination requirements, transportation and Customs -- as well as the location of the nearest decompression chamber.

Extensive coverage of the Florida Keys, California, Hawaii, Bermuda, Caymans, Cozumel, the Galapagos Islands, Caribbean islands, Brazil and Belize.