[RoaldLarsen]

Originally Posted by onelifecrisis

1) Set the TDC to Auto.
2) Go to the periscope view and lock on to the target, then unlock the scope. Between now and step 5 do not move the scope and do not change course.
3) Set the TDC to Manual.
4) The bearing in the TDC will now match that of your scope as it was when you unlocked it (and you have not moved it since then). Taking as long as you need, and using any method you like (map plotting, whiz wheel, etc.) calculate the AOB that the target ship had when it was at the bearing shown on the TDC i.e. the AOB it had when you unlocked the scope in step 2. Enter that AOB into the TDC, along with the target speed.
5) Set the TDC to Auto. You may now move the scope, but you must still not change course. Go to the periscope and lock it to the target.
6) This bit does need to be done as quickly as possible. Calculate the current range to the target using whatever method you like. As soon as you have calculated the range unlock the scope, set the TDC to Manual, enter the range into the TDC, set the TDC back to Auto, lock the scope to the target again (or manually aim the scope at the part of the ship you want to hit) and fire.

Wow!

Of course, that works perfectly. I'm kicking myself for not having worked it out on my own.

Thanks, OLC.