World-renowned naturalists and authors Ned and Anna DeLoach wrote the book on marine-life behavior — literally. Over the years, the couple has authored a series of books covering the behavior and ecology of marine animals in a wide range of diving areas, such as the Caribbean, Central America's Pacific coast, North America's Pacific coast, the Galapagos and the tropical Pacific. Their publications have become invaluble resources for divers across the globe and made them celebrities in the industry. In this video, the DeLoach's offer a collection of valuable tips for spotting some of diving's most elusive — and sought after — critters.