Smoking volcanoes, lush lowlands and over 600 islands rimmed with coral reefs support a marine biodiversity in Papua New Guinea (PNG) that is unequaled anywhere else in the world. The warm Solomon and Coral seas offer shallow snorkeling on fringing or patch reefs, and deeper dives along the sheer walls of submerged volcanoes. History buffs will marvel at WWII wreckage found above and below the sea. Populations in the swelling cities, remote villages and settlements along the Sepik River are as varied as the country's terrain. This guide describes PNG's best dive sites, with full-color photos throughout.