The underwater environment - A fluctuating acoustic medium rich in marine life. Implications for active military sonar

Naval operations are increasingly likely to take place in littoral waters, where sonar conditions are normally unfavourable. At the same time, there is a growing need to consider possible harm to marine life, particularly mammals, from sonar transmissions. This review based on a literature survey addresses both aspects with the aim of identifying technologies and strategies that can be recommended for the military use of active sonar in the littoral. In the absence of a single clear-cut solution, an embracing framework is suggested as an approach to future military sonar design and operation.