how much kicker is needed

[Ken Kurek]

I have a 25 seafari cuddy with a 330 hp I/O. I would like to use the boat offshore and was concearned about the fact of only having 1 engine. I would like to know how much of a kicker i will need to put on the back to keep the boat on course if my primary quits. This concearns me as I know how nasty it can get rather quickly offshore. My primary concearn is safety not a good little motor for trolling. Any Ideas are greatly appreciated.