Wow if thats the case this is one Major bug. Hopefully easily fixed.
Edit just confirmed this in the AI_Sensors.dat file
Entry 13: For AI_Hydrophone Sensor type is set at 2-Sonar and not 3-Hydrophone
Entry 17: For AI_Sonar Sensor type is set at 3-Hydrophone and not 2-Sonar
Easy Fix - Great catch to find that one