Could someone experienced please help me?

[Armistead]

Here explains how the ships course is his AOB.

A US ship so got perfect stad measurments, after two, I click for his speed, you can read the top where it states his speed and course, 8 kt's, course is 327, that is his true course. Now look at the AOB setting left top wheel. I spun the right AOB wheel until his AOB on the left top PK wheel matched his course, 327....perfect AOB. So for AOB you just set the wheel to match his course.



Hard to see, but you can see I've drawn his true course, read the course on the tool and it reads roughly 327.



So you set the AOB to his course, not that it is his course, you can see his obvious course is about 327 on the map.
That clear it up.