the Cold War the US Naval Submarine Force was tasked with keeping tabs on
Soviet Naval movements in particular, the Soviet Submarine Force.
Submarines of the Sturgeon (SSN-637) Class were well suited to this task
and often trailed Soviet submarines for days reporting on their movements
and recording noise signatures. In this image, such a trailing has
turned into a close aboard encounter as a Soviet Viktor III has turned to
port to check his baffles (to listen to see if anyone is immediately
astern). A trailing Sturgeon has stopped his screw and gone quiet.
Extending far behind the
submarine is its towed array sonar which assists in giving a clear picture
of the ocean’s acoustics.