If you have been watching the America's cup in New Zealand, the amount of effort the teams put into technology is obvious. Many millions of dollars has been spent to design faster boats. On a smaller scale this is true for us as well. The AC class was established as development class. To that end, we have seen many new designs in the past years. Most of the newer boats are an attempt to design a better-rounded boat. One that is fast in most conditions around the US. The rule has certain limitations built in. These are to prevent designers from exploring far out edges of the design window. The one that stands out and is direct conflict with the latest big boats is the beam restriction. The full size class has no restriction on beam. If you have been watching the cup for any length of time you have noticed that the boats are getting narrower every year. This is the same thing that has happened in many development classes such as the Marblehead and the US One Meter. I haven't seen an 11-inch wide Marblehead in many years. Why? Narrower boats are faster. This isn't to say that we need to explore 4-inch wide Marblehead’s. You run into the law of diminishing returns. I have computer data that shows that after around 6.25 inches a Marblehead does not get much faster. The full size AC class has other limiting factors that prevent them from getting much narrower. That is, the loads applied to the hull from the rig. In the model class we don't have the same limitations. It would be very easy for a designer to built a 9 inch wide AC boat. I also have computer data that shows a 9 inch wide boat is significantly faster then a 16 inch wide boat. This is why the originators of the model class put the beam restriction into our rule. To keep the class inside a smaller box and make the boats closer in speed