[Pisces]

The hardest part of manual targeting is figuring out how fast the target is, and less hard, what the AOB is. This is usually done by plotting. Determining the amount of lead/aiming is done automatically based on speed and AOB you set. So manual targeting isn't really as manual as you think.

If you set the speed dial on the F5 page Attack map (you should have the manual targeting realism option set), then the TDC automatically calculates the lead-angle: the angle between the periscope view and the direction the torpedoes turn to (gyro angle). And points the torpedoes in the right direction. So, what you want to do, the game TDC already does.

But before you can set the speed or AOB or range dials there is a auto/manual TDC-update switch that needs to be flipped, and back when done. Think of it as a "configure"-switch. In the default state of this switch (auto), the AOB dial is changed automatically as you turn the periscopes or UZO. So you don't have to worry about what it is some time later. Only if you or the target changes course. In this default state it also automatically calculates the amount of lead the torpedoes need to have based on those other dials with reference to your periscope/UZO angle.

So, as vanjast said, basically you just:

set periscope to 0 (or 180 for aft torpedo shot)
flip the switch to manual
set the speed dial
set the AOB in relation to your current periscope view direction (with periscope at 0, set AOB to 90 left or right as it would pass when it is about to get hit)
set the range (only required if the torpedo gyro angle is not to be close to 0)
flip the switch back to auto
point the periscope so the gyro angle dial becomes 000
(! notice the AOB is corrected by the same amount as the periscope change !)
open torpedo doors
(change torpedo depth and impact/magnetic setting if necessary)
wait for the target to come into view on the cross-hairs
pull the trigger!

That's all folks!


Some people have provided charts to calculate this for each speed and AOB setting but there really is no reason to. Except to simulate situations where the TDC is somehow broken.

p.s. leave the torpedo speed setting the same for all tubes (so all slow if you have type-1 and some electric type-2 in the tubes). There is a bug where the torpedo speed setting is not updated in the TDC to the correct value when you select a different tube. This is going to make you miss the target for sure.