Sorry another targeting question

[Pisces]

I'm not sure what you mean with your sub being 'dead straight'. I hope it is straight. Bent subs turn in circles. If you mean straight across the target's path, then yes.

Yes, the torpedo needs time to reach the ship. So before the boom happens the target gets a chance to move also. Depending on it's speed and the torpedo speed this is around 10 to 15 degrees periscope bearing.