I purchased a Shark last year. I didn't have any idea what I had purchased and was going to modify it. When I started digging and found what I have that isn't going to happen. Google, Rod MacAlpine Downie you will get all the history of his designs there. Hell Cat is one that was designed for racing after he went to a race and said he could do better ( he had never had anything to do with sailing at that time) He returned with his new boat design the following year and kicked everyones butt. If I remember correctly He blew them out of the water. I am always looking for info on the Shark and wouldn't mind getting another one. JZ