This reference detailing 1,600 animals with 2,000 photographs and descriptive text is not only the most comprehensive visual field guide to marine invertebrate life inhabiting the waters from Thailand to Tahiti, but also a pictorial tour de force skilfully bridging science and the aesthetic. For the past five years the two authors/photographers have delved deep into uncharted waters, not only visually documenting numerous species for the first time, but also incorporating the most recent taxonomic research of more than 40 scientific specialists. The text focuses on mobile species, highlighting crustaceans, molluscs, worms and echinoderms, however the pages include an overview of attached marine animals, and also explore facets of marine invertebrate behaviour. The guide provides a boon of information for diving photographers and underwater naturalists, known as critter hunters, who enjoy one of the most challenging games in the sea -- searching for charismatic mini-fauna of the reef. And for the armchair adventurers, the brilliant gallery of images brings an unseen, unimagined world to the surface like never before.