Still have issues maintaining depth past 100m, just drop like a brick till i explode or blow ballast.
AI deffinately needs some work, though i've seen our modders on that issue already... spent 8 hrs in scapa flow with only 1 dd taking any interest in me, and all he did was sit stationary pinging me as i went past.... i repaid his kindness by sinking the Hms Barnham and Hms Rodney
(this is according to the map note for scapa flow). Also attacked a task force that chased me from scapa flow towards the western approach, sank another unidentified Queen Elizabeth Battleship and a Kent Cruiser, at first the destroyer escorts were vigilent trying to find me, but at 50 meters and pinging me constantly they still could not see me, and gave up the hunt after about 10 minutes.
More documentation would be nice as I finally found the return to course button, and that was completely on accident, though happy that i now know where it is. Makes me wonder just what other features they've added with out letting anyone know they're there.