Ok I have having trouble with the AOB thing.

I play SH3 and the AOB works differently here. My question is this. I understand the AOB is my position relative to the target. Now does it matter where my boat is facing? Lets say I am pointed North at an enemy ship and it is pointed East at 90 deg. It's bearing to me is 0. Ok AOB is 90. Simple right? Now lets say I am also facing East and the boat is in the same position. Is the AOB still 90? Does it matter where my bow is pointing? Does the AOB stay the same no matter what? This is confusing me.