Yes it's called a sonar. And would they even need to fire the sonar for that? Even using passive sonar they should be able to hear there's a boat above them con

Yes it's called a sonar. And would they even need to fire the sonar for that? Even using passive sonar they should be able to hear there's a boat above them considering how sensitive their sonars are. But operational mistakes can happen no matter how many sensors you have.