@oysteilo: Clearly ShadowHAwk does not understand what I am talking about. 1. Attacker has only subs 2. Defender has destroyer and subs In this case defending subs fire first and any hits are assigned to attacking subs. The attacking subs who are hit do not fire back! hence the term surprise defence! To my knowledge this is the only situation where  the defending side roll dice before attacker! AA guns But it makes sence, really you did not know that there are subs and suddenly you get hit. Does not mather if your moving towards the subs or the other way around. Its just wording, just change it into surprise strike ( think thats the wording in the book anyway ).