The deep ocean exerts a powerful influence on the imagination of all of us, not least because of the scale, remoteness, and its sheer inaccessibility to the air-breathing life on land. This book is the account of some of the latest expeditions of discovery to the middle of the North Atlantic Ocean and the great submarine mountain range of the Mid-Atlantic Ridge. The well illustrated text provides background information, accounts of goals, plans, and technologies, and a final summary of results to date of the Census of Marine Life project MAR-ECO (2001-2010, www.mar-eco.no). By adopting novel technology and the best research vessels the international MAR-ECO team significantly enhanced the knowledge of biodiversity of the mid-ocean ridge system. Illustrations in the book include photographs produced by project partners, not least the renowned wildlife photographer David Shale, as well as historical illustrations of deepwater organisms by Thorolv Rasmussen from Bergen, Norway, and artwork by the contemporary Norwegian painter Ørnulf Opdahl. The author Peter Boyle (deceased) was professor of marine biology of the University of Aberdeen and a cephalopod specialist. Style and contents would appeal to the general readership. Students at high-school and university levels would gain inspiring insight into deepwater geology, biology and ecology and the planning and conduct of a major international research effort.