Hobie 20 is a great boat. Unusual for it to have a spin - I'd ask about the pole and the cut of the 'chute. The boat handles a smaller, flatter spin very well - there were a couple in the Round the Island race out of Fort Walton, FL, every year. There is still a pretty good class of 20s in certain parts of North America.

Check out the somewhat dated but still very useful Sailing Pro Shop Buying Guide for good tips. Also check out the Hobie Class website for class rules and links to the Hobie forums and tuning guides.

Happy shopping -