after stealing enigma?
 

How do you escape after taking the enigma & wrecking the torp? I haven't got id papers to show the guards. So they keep searching and raising the alarm

You can easily find a permit inside the submarine, at the back, on your left in the bunk.

I sorted it not long after posting, missed a button in one of the top rooms which drops a torpedo onto the floor and makes the guards run out to check what it was.