Early Question

I appology in advance for questions thant can by already answered.
But during my reading some question came to me.

If I understand corectly all ship can turn at 90° once par turn ? no distinction betewen battleship, cruiser and destroyer ?

You are correct. This is because turning circles could vary wildly. For instance, a Fletcher class destroyer would have a notoriously big turning circle and would actually get out-turned by larger ships, even battleships. So for our level of abstraction I decided to keep things simple.