Did you know that when beneath periscope depth, The USS Albacore relied on two types of sonar?
Passive sonar was used to detect noise from sea creatures, weather, or other ships. This type of sonar only gave the operator a direction of the sound.
Active sonar involved transmitting a sound wave into the water and listening for the retuning echo. This echo would then give the operator information including the bearing and range of the sound.






