[Pisces]

We are talking the US TDC right? Or German? As the Uboat-missions addon allows the Germans in the pacific theatre too.

It would be correct to aim mid-ship of the target. Only pointing at the bow would cause it to miss halve the time when your errors are on the front side of it. Best is to even those out. It is best to point consistently at a easily distinct marker on the ship like a mast or funnel or something spike-like. But a front/back wall-face of a structure might also work.

The US TDC has the option to input a range (with the stadimeter) and a bearing (just by pointing to something) and send it to the TDC. When you do that again after a certain time in between (minutes rather than seconds to average out any position errors) then there is a button to ask for the solution. Then you get the target course (or AOB, I forgot) and speed between these positions. You can use those to set the AOB and speed dials in the TDC. But any torpedo fired from then on will assume that last bearing set to be where the target is. It will lead the torpedo according to the speed and AOB as set. But as the target moves away, any delay in firing from the last bearing will cause it to fall behind. That is why you need to use the Position Keeper that updates the position of the target as it goes. Based from the last bearing and range, and set speed and AOB/course.

So if you know the speed, set it right away. If you know the AOB/target course. Set that too. Then turn on the position keeper. This starts the position calculations. But with a false position as no bearing/range was set. Don't fire a torpedo yet!!! Do a bearing/range measurement on the mid of the target and send it. Now the TDC is getting the right approximate updated position of the target. Why approximate? Because the AOB might have changed during setting it in the TDC and the first bearing fix being sent. But in the short term, it would be correct enough to fire a torpedo. After a few minutes you can do a 2nd bearing range fix. Let the TDC calculate the speed/AOB solution, and update them and send it back to the TDC. Now the position keeper is properly synched to the target movement.

Personally, when it comes to learning and training targeting I wouldn't use salvo spreads. As then you have multiple torpedoes going out. And you don't really know which one of them was pointed at the aiming spot. Go for single shots to verify/learn how that TDC setting turns out. Single shots should explode on the place where you aimed the periscope at. If you get a dud, it means it hit a target. So your job with the TDC was well done. I would only use a salvo in a campaign patrol (when tonnage is important and stuff actually needs to sink) to account for premature detonations, dud-hits and if I knew 1 torpedo warhead wasn't enough to sink that size of the target.