As a result of past military training and weapons testing activities, munitions are present at thousands of current and former DoD sites encompassing millions of acres. Many active and former military installations have ranges and training areas that include adjacent water environments such as ponds, lakes, rivers, estuaries, and coastal ocean areas. SERDP and ESTCP sponsored a workshop to allow government managers and investigators to explore ongoing work in related fields that may be applicable to underwater munitions sites, as well as to identify gaps in understanding that must be addressed by future research. The goals of the workshop were to establish guidance for DoD’s future investments by identifying gaps in capabilities that could be addressed through integration and demonstration of systems based on existing technologies and gaps in understanding that must be addressed by basic and applied research in phenomenology, sensor development, signal processing, and supporting technologies. Technology-specific research and demonstrations are described in the Workshop Report.