You can't use the NACA 0012 profile because of the thickness restrictions in the class rules. The first two numbers in a NACA section describe the camber (0%, because it's a symmetrical foil) and thickness (12% of the chord).
From the class rules:
The maximum thickness of a rudder blade(s)
shall not exceed 1.015 in. (25.8 mm), tapering
over a distance of 2 ft. (60.96 cm) to a maximum
thickness of 1/2 in. (12.7 mm), 2 in. (50.8
mm) from the bottom tip of the rudder.
The maximum chord is ~ 9.75 in, so the max thickness is 10.4%
The planform is dictated by class rules - and doesn't have a linear chord progression (like the thickness is required to), so the section changes as you progress down the foil.
Having fun yet?
Beware the "low drag bucket" sections, like NACA 63 series. They're meant to operate at a low angle of attack - they will stall at higher angles - and well before a 0010 section. The laminar flow characteristics are useless in a disturbed flow regime - like the flow coming off a Hobie 16's leeward hull.
This was one of my textbooks in naval architecture school 30 years ago, and it's still applicable today - http://www.amazon.com/Theory-Wing-Secti ... g+sections
Get the Kindle edition for only $15 and your head will explode with information.