Another two bugs I found that I must mention:
The attack periscope ship identification system is almost
DOWNRIGHT BROKEN at night against stationary ships. I can see the docked ship plain and clear as it is no more than 500 meters away, and yet my periscope fails to recognize it as a ship at all. In a stormy weather at night, I can be literally 10 meters away from a docked ship and my periscope still won't identify it as a ship.
However, when I surface my ships on the exact spot, my watchers always inform me of warships being close by, and enemy ships will attack me in kind, thus ruling out the fact that they may be merely decoration objects.
Second bug is that whenever I reload a save while submerged in the water, my sub will always be at the 11 m depth, semi submerged but my watchers are at duty on the bridge....
And even when I set it to silent mode in the save, after loading the save the sub will be in non-silent mode. Pretty annoying.....