One of the things which the IWCA rules specifically prohibit is a tiller extension. On my Wave, I have the new EZ-Lock rudders, which have very short tiller arms; so I have added a tiller extension, allowing me to sit farther forward to balance the boat. (Something I learned from reading Rick's book.) To legally participate in the IWCA-sanctioned regattas, I removed the tiller extension. No big deal.

Since all Waves came with Hobie sails and stock rudders, couldn't the folks who choose after-market sails and rudders for IWCA racing, simply put their stock ones back on for HCA events? IndyCar racers use different wings and foils for oval tracks vs. road courses. It's just a different set-up for different events.

I'm an advocate of stock boats, because I think it's such a great boat out of the box(es)! But I don't think anyone should be turned away (or dis-invited) who wants to race. Maybe a PHRF-type adjustment could be used for stock-vs-custom, if it makes that much of a difference.