Sonar

Robin W. Baird / AP Photo/ Cascadia Research Collective

Active sonar is the Navy’s best weapon to detect the presence of hostile submarines. But that same powerful underwater pulse of sound can harm or even kill whales and other marine mammals.

Now, the Navy is seeking permission to continue using a huge swath of the Northwest coast, from northern California to the Canadian border, for a wide range of naval training and practice, including sonar. The Navy says it’s taking precautions to protect whales, but others say it’s not enough. 

Hugh E. Gentry / AP Photo

A judge is requiring federal regulators to reassess permits that allow the Navy's expanded use of sonar in training exercises off the West Coast.