If you really where a 20+ year submariner then you should already know the screw is not the loudest thing onboard by a long shot. Also if you bothered to read

If you really where a 20+ year submariner then you should already know the screw is not the loudest thing onboard by a long shot. Also if you bothered to read the full article they are not using just sound to detect. Granted this would only pertain to some of the current fast attack missions in regards to some countries. SEAL delivery is a relatively close up mission considering how big the ocean is.