Growth on rudder

[Raider Ron]

Late last season I started having a steering issue with my downeast boat.
If I didn't hold the wheel it wanted to turn to port and as I suspected, when I hauled out I had quite a bit of barnacle growth on my rudder (most all of the port side)
I was really shocked seeing this considering this boat never sits at the dock for more than a day or 2.
I'm looking to avoid it happening again this year.
I'm guessing 1 option would send a diver down to scrub once in a while.
I'm thinking another option is painting the rudder & shaft.
Any opinions on painting it, good or bad, what paint to use ???
My rudder is a VERY large stainless plate rudder.
Thanks