Question about U-jagd

[ChaosDuck7]

does the boat have to be moving perfectly 90 degrees for the reading to be accurate? What if its moving at a sharp angle?

[gutted]

+-30 degrees from 90 should be ok. Also be sure to cancel out your relative movement. Either by coming to a complete stop, or by pointing your sub toward the target ship and measuring as it passes the 0 bearing in your scope.