@Caesar:
Ok, lets take a step back.
So, should Subs be able to bypass Denmark and go into the Baltic? Who cares, really? Lets just say the house rule is subs can enter the Baltic Sea. Is the UK or USA going to invest in subs to enter the Baltic for the sole purpose of killing off the German fleet? There are no convoy routes in the Baltic so that is in essence the only purpose of them going in in the first place.
Germany has a DEST with their fleet and a AB on W. Germany with planes. It is a suicide mission by the Allies to send in a sub or 2.
In the big picture of the game, it is a total non factor.
Same scenario with Italy. Lets say the house rule says subs can go through the Suez. What? UK is worried about a stack of 6 Italy Subs rampaging through the Suez? It is not even a point of discussion and thus a non factor.
Except the Suez and Panama are a moot point because those are canals that have locks which I agree doesn’t make sense however in the context of the Turkey, Denmark, and Gibraltar, submarines could in theory sneak pass these zones and historically speaking, did.
Denmark strait was pretty heavy mined, there where nets and underwater microphones. So yes a lone sub might get through but not nearly viable enough to make it for the context of this game. Units are not just a single unit they are a group of said units. Scapa flow was also at risk from subs with its many outgoing channels and yes 1 sub managed to get in it does not mean that the whole base was crap.
Well Allies going into that German area is foolish. Home Fleet just blockaded that region anyways however the others had enemy and neutral ships passing all the time.