Sail Area variable
PD Racer, designed by Shorty Pen in 200?, inspired by the Bolger Brick design but a sailboat. A simple and easy to build design. This developing class is gaining in popularity and has an active racing program. The class rules allow for experimentation and many boat modifications yet boats cost very little to build.
Shorty tells all about it on the FurledSails Podcast #100
For full information on the PDRacer see Shorty's PDRacer website
There's an Australian site about the OZ PDRacer, which sells plans for their "improved" PDRacer.