Well, yes. If I'm submerged by a convoy and my sonar man detects say three of the lot, I hit the outside view key (.), I see just the three ships my sonar man has detected. This also happens with my scope and uzo. Not until you lock it and identify does it become a viable threat or target or both
. So, when my sonar man detects all the ships then I can hit (.) and see them all and they register as merch or DD when listening at the sonar station. A noise is just a noise and a sighting is just a sighting until you identify it by locking or sonar man can identify.