This decision concerned an application for a preliminary injunction, brought by the Natural Resources Defense Council and other environmental organizations, which sought to stop the Navy from using, in most of the world's waters, Low Frequency Active ("LFA") sonar. The Judge considered that the plaintiffs were likely to prevail on the merits, having shown the likelihood of irreparable injury, on the basis of various legislative requirements. The Court requested the parties to agree on a tailored preliminary injunction, which permitted the use of LFAS for testing and training in a variety of ocean conditions, but provided additional safeguards to reduce the risk of marine mammals and endangered species.