This research service outlines efforts of the United States Department of Defense to upgrade sonar technologies. Operations, procurement, research, and services spending are summarized, and a sonar spending forecast is included. This study indicates aspects of sonar products and services spending emphasized by the Department of Defense so firms can invest in these growth areas. Also included are success factors for operating within the sonar market, drivers, restraints, sonar goals, technologies, programs, and competitors. The base year for financial spending is 2010, and the forecast period is 2011 to 2016.