Just to clarify though, if a sub hits a battleship with a kill shot (meaning that it was previously damaged by another hit, and the sub’s hit indeed killed it), the battleship sinks immediately like any other sea unit would and gets no casualty shot.
Example 1:, I attack your battleship with a sub. In cycle 1, I hit you (damaging you), and you miss me with the defending fire. In cycle 2, I hit you again, and you sink immediately without a casualty shot.
Example 2: I attack your battleship with 2 subs, and manage to get 2 hits in cycle 1. The first hit damages you, the second hit kills you. Your batteship sinks immediately wihout a casualty shot.
~Josh