Rudder Blade Pitting

My rudder blade is showing signs of pitting. Is there a way to refinish or smooth it(wetsanding) or is it best to replace it?
I am not concerned about it for day sailing but want to get input for racing.

Get 1 or 2 spray cans of Rustoleum sandable primer, depending on the extent of pitting. Spray on and sand. Leave the primer finish. It will look like new. GK FS3512