Maybe unrelated or simply stupidity on my side. I just got shot from 95%HP (upgraded hull) to 0% in a single salvo from what I think was a IV Battleship on my Kuma. Most hit me in my side, while I was trying to turn away from the ship. It was at about ~7KM distance.
I effectively got one-shot. ...how is that normal? It sure as hell never happened to me before.