Technical term for sonar equipment, literally 'sound-wave underwater detection device'. Used in military, maritime, and scientific contexts.
The submarine detected the enemy vessel using sonar.
The katakana loanword ソナー is more common in everyday and general contexts, while 音波水中探知機 is a formal, technical Japanese compound.
Compound of 音波 (sound wave), 水中 (underwater), and 探知機 (detector). A native Japanese coinage for sonar technology.