Book excerpt: Although our oceans are some of the most beautiful and diverse environments in the world, most people know very little about the ocean's ecology or just how much humans depend on the oceans for survival. The Complete Idiot's Guide' to the Oceans will be a marine-lover's reference for mapping the world's oceans and their exploration. Authors will provide key illustrations to help readers understand important concepts along the way with a color photo insert presenting a wide array of marine creatures and habitats.