I play at low realism level, just because I play this game for not too long now. I am happy that I can hit something. But I am working on my manual targeting skills with a self-made mission, sinking 4 different kinds of ships.
Getting even 1 hit on a well protected convoy is still hard for me.
I really don't like the limit of fuel. If I want action, I want that, without having the limit of fuel. So you are not really alone
