I've shot at targets completely blind about 2 or 3 times... but it is so much work that it just isn't worth it. The times I've done was when the weather was so bad that you can't see the target unless your within 200 meters in range (to close to fire).
The point is that: it is possible, but to do it you must cheat a little in compensation of a few things that are missing from the game's sound model (Greyriders mention of sound pitch is one important issue, for example)
Things to remember:
* Close range is within 1 km.
* Medium range is more than 1 km, but less than 3 kms.
* Longe range is more than 3 kms., but if your sonar operator can detect the ship, then it's likely less than... oh, let's say.... 13 kms... maybe, it's hard to say since experience and fatigue (we beleive) has a lot to do with how far your sonar operator can hear things... Oh, and weather affects too... and of course your own ship's noise (all stop on the engines is recomended)... oh! and also how deep your sub is.... and there's also that thing about different hydrophone models being available int the game... and then there's also.... ah the hell with it! let's just say 13 kms and pretend we're right.
* If your sonar guy can't detect the target but you can if you man the sonar yourself (something which is incredibly common), then the target is likely farther away than 13 kmts. but definetly less than 32 kms., which (I beleive) is the farthest that anyone has reported hearing anything.
With that you can draw bearing lines that you know that the target must be within at different moments in time. After a while, you can easily figure out the ship's track by drawing a straight line that crosses al these "bearing lines" that you have drawn.
Note that for this to work, you don't care about the target's exact speed or identity, but you do need to be able to stumble into a target that is traveling slow enough for you to outmaneuver.
Here are some pics, let's see if you can figure them out.
The setup:
The result (yeah, burn baby, burn!
):
The setup (case two):
This one was a hell of a lot easier, since it resulted from a radio contact, so I knew where the track originated from (thus fixing one of the line's end points).
Anyway, here's the result:
Yeah... your not so invisible now, Tommy, AREN'T YOU?!?!
You can't really hide if your BURNING LIKE A DRIED UP CHRISTMAS TREEEEEEE you stupid piece of !#$@
!!!!!