guy, after 1.3 it's very easy to at last calculate the AOB w/o resorting to "gesstimates". to get the AOB, do this... say visually track, identify and lock ur target. calculate range (with the dial) and send it to TDC. then wait. (with lowered periscope.) later (about the time u think u'll take the shot,) goto periscope, and lock ur target again. calculate range (again). and it u did it well THEN u can ask ur officer to give u a good estimate to the target's speed pressing the "chronometer" button on the speed TDC dial. the officer has not only given u the target's speed, but also its heading. NOW u goto buisness! click the AOB dial and on the opposite side of the screen (see the target position dail as well as the angles of ur torpedo and its hit according to ship?) the upper dial on the left. it shows the ship's heading in relation to the AOB. now turn the right AOB dial untill the target's heading is what the officer said it was in the upper left dail! understand?
http://www.subsim.com/radioroom/showthread.php?t=118923 this'll explain it better.