i will try to help you understand AOB. i will explain to you AOB, as i understand it, and i have no problem with estimating AOB, and course, just by looking at the ship, theres got to be a time
when you have to trust your own judgements, if you want to be any good, really.
i have some pics to demontrate AOB for you.
the way i see AOB, it is the angle i see of a ship, from my line of sight, to the bow of the ship. my line of sight is always the aiming wire of the periscope.
in pic one, you see my scope and aiming wire, the aiming wire always represents a zero degree AOB to me.
now in pic 2, im going to put a ship there, and when i look at the ship, all i can see is the bow, not port or starboard sides. since
all i can see is the bow, im going to call this zero degree AOB.
since the target is at my zero degree bearing, and heading straight for me, his course is 180 degrees, taking the targets bearing of zero degrees, adding 180 degrees
to its bearing, since it was 180 degrees or less, adding or substracting AOB, which in this case is zero, and theres your course and AOB of the ship.
now in pic 3, you see that the angle is different than the previous example. the bow is off my line of sight, which is the aiming wire of the scope, twenty degrees.
since the bow is twenty degrees from my line of sight, and i see the port side, this is called 20 degrees port. the ship turned to its starboard side twenty degrees.
course would be: zero degree bearing, add 180 degrees, add AOB, since its a port angle, of 20 degrees, and its course is 200 degrees.
now in pic 4, the ship turned some more. the angle of this picture is deeper than the previous on, so it was a greater numerical value, this angle is 45 degrees port.
on the ground, if the ship was moving on its couse, the deeper its AOB, the father away he will pass you.
the course for this ship is bearing 0, less than 180, so add 180, then add AOB, its its a port AOB, of 45 degrees, and the course is 225 degrees, 0+180+45=225.
in pic 5, the ship was turned again, and now you can see the wholw port side, from bow to stern, this is a 90 degree AOB. its has turned 90 degrees to port from my
aiming wire/line of sight.
course for this ship is bearing 0, bearing less than 180, add 180, then add AOB, since its a port AOB, 0+180+90=270, the course of this ship is 270.
in pic 6, we have come back to the reference point again, cus now we will go to the starborad side for AOB'S
in pic 7 , the ship's bow has turned left, and his bow is twenty degrees to starboard from my line of sight/aiming wire.
this AOB is called 20 degrees starboard, since all i see is the starborad side.
course for this ship is: bearing less than 180, add 180, subtract AOB, since its a starboard AOB 0+180-20=160
course for this ship is 160 degrees.
pic 8 is 45 degrees starboard AOB, course for this ship 0+180-45=135 degrees.
pic 9 is a 90 AOB, you can see the whole length of the ship, on the starboard side, so it is 90 degrees starboard AOB.
course for this ship is: 0+180-90=90. ships course is 90 degrees.
that took care of acute angles, and targets that are closing, i hope that helps, i dont want to get into obstruse angles if i dont have too.