Paxi,
In answer to your question, I don't know for sure. But I do know that the hull is constructed with a blister-resistant ISO NPG gelcoat. This is done, of course, at the factory. A dealer option for that boat was (is??) 5 coats of epoxy barrier paint & 2 coats of bottom paint. I assume that the rudder received the same treatment; but, a quick email to Hunter would resolve your question.