It's *dark*!

[sergei]

Originally Posted by schlechter pfennig

Not that I'm complaining, mind you. When you're far out at sea, with no moon and full overcast, it should be really dark. But if I'm having such trouble spotting ships, do the enemy have the same trouble spotting me?

Welcome aboard
As long as it is early war, meaning the enemy will not have radar, then yep, you can get real close and they won't spot you.
After the torpedoes go boom expect every searchlight in the convoy to come on.
Be prepared