Baffles (submarine)

Baffles are the place in the water directly behind a submarine's propeller where conventional sonar cannot see. The blade's motion through the water creates acoustic distortions and noise which an enemy ship can follow and not be detected. Baffles can be cleared by executing a Crazy Ivan. Shadowing Soviet submarines, in their baffles, was a popular technique used by U.S. Navy submarines during the Cold War.