Naval Ships and Submarines Practice Test

Sense in submarines is dominated by sonar. The two main ways sonar detects targets are passive and active: passive sonar listens quietly for sounds made by other ships, submarines, or marine life, gathering bearing and sometimes range information without revealing the submarine’s presence; active sonar emits a sound pulse and then listens for echoes, allowing the system to determine both range and bearing to a target based on the returning signal. This combination is standard because sound travels well underwater, enabling detection at long distances while staying covert when using passive mode and gaining precise range data with active mode when needed.

Radar and infrared cameras don’t work well underwater, and lidar and chemical sensors aren’t used for standard target detection in the submarine’s operating environment. Magnetic anomaly detectors and weather radar are not the submarine’s primary onboard tools for detecting targets—MAD is mainly used from aircraft to locate submarines, and weather radar serves meteorological purposes, not target detection.