Ahoy Lynard
I would'nt worry about manual targetting too much,you'll soon get the hang of it,what is more difficult is playing with map updates off,which for the first time in my current patrol i'm doing,which gives me 100% for the first time in my career
Just a quick tip for you about manual targetting.Say if you are travelling on parallel course with a ship that is going say bang west at 90 degrees,before you do any work in the TDC make sure you don't have the ship locked on just yet.Make sure both bearing and AOB are reset to zero positions in the TDC.Flip the manual switch until the green light comes on,indicating you are now in full control of the torpedo launch angle.Now bring the bearing to 90 degrees and the AOB dial round to 90 degrees port,making sure all other settings are correct.Regarding speed I always add an extra 0.5kts if I am greater than about 2000m allowing the torpedo to run slightly ahead practically shearing his bow off.
At this point you should now lock the target in the scope/uzo.
Now,flip the switch again and the red light comes on,telling you the torpedo launch data is all set and ready for firing,the TDC will now automatically update all data as your AOB changes.When target is just starting to pass the 90 degree point fire,and you will have virtually a perfect shot everytime,unless weather conditions interfere naturally.
You can use all the above for perpendicular or zero degrees firing,just make sure the bearing is set at zero and the AOB is 90 degrees P or SB respectively,the TDC will correct exact values when the switch is flipped into the red.
Hope some of that helps a bit.
Very important
After each attack always make sure you flip the switch again and reset the bearing and AOB dials,as if you don't it can cause all future torpedoes to fly all over the place,and is very annoying