using True Ship dimentions I get NOTIN'!

[Crawlerz]

firstly, im not very experienced when it comes to MANUALLY targeting ships. so i have to pause. it all happens sooooo fast for me. it'll come w/experience i suppose.
secondly, i finally figured out why my torps weren't hitting anything. i used the spread angle to the WRONG side! left instead of right. i corrected and hit the snot out of that Mogami!
but a training scenario under controlled situations where no one's shooting @ u, is another story from a japanese battleship convoy. i managed only one measely aircraft carrier sunk before they all went every which direction they wanted. just like random specs of dust. how does one deal w/that? i mean u score ur first (usually silent) kill and then after that they all take evasive action! vzzzzt. it will be impossible to catch any of them, even the battleship coz it can slow down and turn too. u'll just use up all ur torps!
help? thnx!