Collection of papers detailing more than a dozen different ways that scientists around the world are using GIS to shed new light on the depths of life beneath the waves. Among the topics covered are recent technical advances in mapping, charting, and visualizing in three dimensions, from coastal areas to the deepest parts of the ocean. Also examined are ways in which GIS can help integrate diverse fields of marine science - even the ways that GIS can be used by the Mediterranean cruise ship industry.