It just seems appropriate, and unlike the Europeans, we can use metric and imperial equally well. I can tell you now that there is no bug in the targeting system. The targets also do not seem to accellerate when they see a steam torpedo coming their way as GWX targets will do, especially during the daytime.
Today I have a Tennessee BB and a T3 Tanker bagged, along with three smaller prey. Make sure you get in to about 500 yards if you're missing. That will make any errors less significant. Make sure you use your attack map to check your setup. You'd be surprised how often that saves my hind end.
Take it slow and try to figure out what you're doing wrong. I'm really curious what it could be! Hope you can turn it around quickly.
