Thanks fellows all good advice I'm sure. Hehe my fault for going in the lion's den I s'pose. My actual surface speed at flank is currently 5 kts so no worries there but it's my submerged speed that's the killer! And I imagine if I lose the other prop I'm screwed right? Funnily enough despite the stb prop being 'destroyed' the underwater animation still shows it rotating!? Go figure...
I still can't believe I headed straight for an Allied airbase! What a Bernard I am!