Acoustic remote sensing of the ocean environment has seen a remarkable progress in the last ten–fifteen year as a result of an increasing understanding of the experimental techniques and procedures and of the subtleties of the interaction of sound with complex physical and biological processes. This is particularly true in the shallow water environment, where acoustic methods have the potential to allow for a fast and accurate characterization and assessment of the environment. To review the state of the art and the research progress in the field, a workshop was held in the island of Ischia, Italy, in June 2004. Special emphasis has been placed on the experimental applications, to realistically assess their potential and capabilities of the methods proposed. This volume, based on the workshop presentations, include a range of diverse and innovative applications, as well as comparisons in the field among competing approaches and review papers.