No problem concerning your opinion mate. We can agree to disagree.
A quick addenda though, in my personal experience with
perfectly zeroed and computer-assisted light, medium, and heavy land-based field artillery fires... it is an infrequent thing to hit the exact point of aim repeatedly. (Even when the firing unit is stationary in "direct-fire" mode/configuration... and the target is also stationary... in perfect environmental conditions.)
In SH3 you must remember that both you and your target are always moving in three dimensions. (Even when it appears that conditions are flat and calm... your U-boat is moving) From the U-boat gunner's point of view... it really SHOULD be annoying!
Remember, your point of aim is just that... a 'point of aim.' Adjustment of your fire should typically be necessary... be it azimuth or deflection... or reducing your range to the target.
In GWX, the sea state does increase/magnify/further degrade deck gun inaccuracy as it should. The rougher it is, the more inaccurate gunfire is. This isn't random. It is logical and linear.
Just leave your mind open to change. Clay Blair's works may shed a great deal of light on the subject for you.
Besides, if it was easy... why would U-boats (or any other submersible) need torpedoes?
Sink'em all!
[EDIT: If you are a player manning the deck gun yourself, the deck gun sights remain 'inertially stabilized' and this is a stock SH3 bug. Deck gun sights do not pitch and roll with the U-boat and deck gun itself as they should. The 'inertial stability' of the deck gun sight is a separate issue from the accuracy of deck gun fire point of impact variance. At any rate the deck gun sights simply show your point of aim. In GWX, for those that are interested in playing with a more historical approach, it is recommended to let your crew do the shooting. U-boat captains had additional responsibilities during use of the deck gun as it was, and this method allows you to avoid the gunsight bug altogether.]