Any good advise for aiming torps?

[U-418]

Here's my sroty.

Because I'm new at this I spend time on tutorials. To get used to the controls of course.

The torp trial.

(oh I forgot to mention this, No mods. Gart wont allow any on his computer. And I don't have DVD-ROM on my computer )

Anyways...

The first two ships go down with ease.
The third ship, I missed once so I chased it and let her have it up close and personal. Not smart in a real situation but this is just me learning to use torps.
The forth ship, I chased and disabled her engine. So at 200 meters of distance apart from her on the surface I fire a torp. It missed. I try again. Missed again.
and missed again...Although The Aft Torp hit the ship. After that it was time to quit.

End of Story.

Gart wanted to play his World of Warcraft game. it was late noon. So here I am watching the boards like a ghost in moonlight...???...
Right, I start playing early as 8:00 AM in the morning while my brother 'Gart' sleeps.

...

any good advise for aiming Torps?