Part way down this thread there is a way to show the player sub plus other ship icons on the map, I did a screen-shot to explain plus a screen-shot on the last post to show how the icons appear.
http://www.subsim.com/phpBB/viewtopic.php?t=43134
This isn't quite what you want here but it may be on the right track,
I asked on the mission section how to get spawns to appear, I have a feeling it is there but it needs a bit of experimenting to hit on the right sequence etc.