TT's Foils and Course boards all in one race.
That is the future.
Why not? If you look at every form of racing from yacht to motorcycles to horse racing, just level the playing field via a handicap system then, the trick will be picking the most appropriate equipment for the conditions.
And best of all an "Open Class" format doesn't need to be IKA / ISAF etc... just get some mates together and race! If you feel you NEED rules then ask your local yacht/windsurfing/catamaran club etc... if you can join in to their racing.