I sank that battleship the night before last - took me 3 attempts (save - reload). That's not an easy one to sink as it's really travelling quite fast , so I wouldn't worry about having trouble sinking it.
Might I suggest having a look at this thread:
http://www.subsim.com/radioroom/showthread.php?t=164131
It's the SHV TDC tutorials thread - covers all types , manual and auto.
Then I would reccomend saving just before you attack. If it goes wrong you can reload and practice till you get it right.
Either way good luck - let us know how you get on.
Edit to add: Sometimes I have trouble getting a lock too - it's really frustrating as you can see the ship quite clearly and yet for some reason it wont lock. You just have to wait till it does.