It's been said that the Kona is a problem class because you can only buy from one supplier - but for many people, that is not a problem but a plus. Some of us just don't want to get into a gear race. We don't want to spend our time working out whether a Brand X 2006 model mast works best with a Brand Z 11 or a Brand Y 11.3421......we just want to go out and become better sailors, and to know that when we win, we win because we sail better and not because we have spent more money, or because our sponsor has superior designers. I leave my fastest gear in the rack and race one design because I just cannot see the challenge in beating the fleet because of the stuff I own rather than because of how I sail. I also want to be able to sail when I want to sail, not wait for wind to get a decent day out.
However, of course, lots of people DO like tweaking their gear, and getting the ultimate in course racing planing performance. They don't want to sail something slower.
The problem is that given these very different extremes, any attempt to get 50 people to race windsurfers in an area on just one class may rule out too many possible racers, no matter what you do. There are always plenty of people who love FW and would not sail RB or Kona, and vice versa. The problem is that windsurfing seems to hate the idea of diversity amongst racers - the manufacturers want everyone to race in a small number of classes. That ignores differing tastes and conditions. Sure, numbers breed strength in some ways but not if you are leaving people out by not giving them a class that they find acceptable - maybe not ideal, but acceptable.
It may be more difficult, but a two-pronged approach could be a very good way to go. Maybe something like a Kona class and a FW class, since you have such good winds. People who like to sail in all winds and want cheap new one design off-the-shelf gear can sail the Kona, guys who want the ultimate in performance can sail FW. Actually wouldn't a Slalom class be likely to attract big numbers in 12 knot+ winds??
We have a total fleet of 50+, with 30+ racing on a good day. There are three classes - Raceboard, One Design and the kid's OD. Without the three classes, I don't think we'd get the same numbers overall as too many people would be unable to find a board to suit their tastes. However, we are sailing on a small inlet where FW and Slalom don't really work.