This mod is gives you a 360 degree bearing tool overlaying your sub when zooming in on the normal map or the attack map. It basically gives you bearing and distance to target by simply looking at the targets location in relation to your sub.
As for the editions of the game...
that's pretty obvious, Normal edition= the game DVD, normal case and manual + keyboard hot key card. The collectors edition is simply, nice big case, game DVD + some other goodies that one don't really need unless you are a real fan :p check this link
http://www.amazon.de/gp/product/imag...2&s=videogames