In submarines active sonar is rarely if ever used. It will give you away instantly to anyone around you and then you give enemies your unique sonar signature. C

In submarines active sonar is rarely if ever used. It will give you away instantly to anyone around you and then you give enemies your unique sonar signature. China and Russia could easily say Seawolf XXX is the South China Sea right now pinging around. This is SIGINT 101. Submarines have the same radar and sonar we use for fishing when they are navigating public waterways and inlets. They do not use the military grade stuff in those situations.