We have used a method of sailing different classes / boats with varying handicaps at club level quite successfully, it goes something like this :
We take the handicap rating for a boat/group of boats, and calculate it`s corrected time in a 1 hour race. We then do that with all classes / boats at the event, before racing starts. We can then determine how much time each the faster boats would give the slower boats in 1 hour, we then have staggered starts at the time intervals calculated, so congestion at the start line with boats that rate differently to you shouldn`t happen. The Race Officer then lets us race for an hour, doing as many laps as it takes. Class winners can be scored separately, for the purists. The nice thing is it turns into a pursuit race, and if well-run can lead to some very exciting finishes, with all the congestion at the finish line ! This way the spinnaker boats start last, and have to catch up to the fleet. Also means that the faster boats don`t have to wait around for the last finishers for too long before the next starting sequence gets under way. It ain`t perfect, but it`s fun, and fun is what makes people sail.