Wouter,
These lighter weight boats are not a technical breakthrough for beach cats. Prepreg construction and the autoclave were used to make spaceship parts and airplane parts and race car parts long before they were used to make beach cat parts. As a matter of fact I have been told that Marstrom built glider parts long before he built beach cat parts. The use of prepreg materials and the autoclave in beach cat construction is not an invention. You cannot get a patent on it. It is a construction method improvement but it is not a technology breakthrough.
Square top mainsails: Nothing new! If you look in an aerodynamics text book, Aero 101, you will find a section that deals with wing spanwise efficiency. There will be a curve of wing span efficiency or effectiveness vs wing taper ratio. You will see that the wing shape that looses the most span effectiveness is the wing that comes to a point at the outboard end. As the wing tip chord approaches about 25% of the root chord, the wing spanwise effectiveness rises rapidly into the low 90% effectiveness
range and then the curve levels off with further increases in tip chord to root chord ratio. When the tip chord to root chord reaches a value of 1.0, the spanwise effectiveness begins to fall off again because of the large tip vortex caused by the wide wing tip chord. I had a mainsail on my SC20 with a 2ft wide tip chord in 1978. My first RC27 in 1983 had a square top mainsail. When was the first time you saw a square top mainsail? Did you notice that today even the Americas Cup boats are using square top mainsails? These so called "hi tech" boats are following the lead of the beach cats with higher fineness ratio hulls and high aspect ratio sailplans and keels. Today these boats require 20ft of water to keep from dragging their keels on the bottom.
Prebent Rig: Again this was a standard item on the early RC27s. As soon as I began experimenting spinnakers, 1983, I ran into the mast inverting problem. Sweeeping the spreaders aft of the mast 4 to 5 inches created two tall slendar triangles of fore and aft mast support which pushed forward on the central height of the mast and prevented mast inversion. The first spinnakers I put up showed NO improvement in boatspeed and no change in downwind sailing angle. The spinnaker filled and the mainsail became totally ineffective; no net change. It wasn't until the late 1980s that spinnakers began to work to advantage on the RC boats and that was after the purchase of several spinnakers from several different sailmakers.
On the ARC boats you and others have missed the whole point. To go faster a sailboat must have a higher sail area to weight ratio. There are two ways to get there. One is add more sail area. This is inexpensive. The other way is to reduce weight. The Tornado is an example of this. An Olympic Tornado costs almost twice as much as any other 20ft beach cat. Which way do you think the sailing public would rather go? The other very important point that goes untalked about is boat width. To be faster than other boats a superior design must have a higher righting moment to sail area ratio also. Without this parameter being superior to other designs, the higher sail area to weight ratio cannot be taken advantage of. Also the narrow boats with high sail to weight ratio area drive the competitive sailors weight to larger people. The SC and ARC products are unique here. These designs offer the 12ft beam which lets leverage do the work of generating more righting moment rather than requiring a larger weight person. Why do you think the Tornado is 10ft wide and always has been? It is not just because the designer thought it looked pretty. It has a very functional purpose. Nobody is going to build a boat faster than the Tornado until it has a higher sail area to weight ratio and a higher righting moment to sail area ratio!!!
Bill
