Why not constrain what really matters rather than putting artificial constraints on sail area or length? If you ask the wrong question you are unlikely to get the right answer.
1) Cost. The average annual cost over the lifetime of the boat is really important to many of us. Do I need to buy new sails every 2 years? What else do I have to replace on an annual basis? Will the hulls go soft after 10 years of hard sailing? Do I really need to pay an extra $2000 for carbon pre-preg hulls or can I spend $200 on a larger sail plan and go just as fast?
2) Real Performance. Is the boat still fun to sail through powerboat slop when the wind is gusting to 11 knots true? Can I make it home in one piece when the wind cranks up to 30? How wide is the range of conditions that the boat is fun to sail? Some of us have to plan our sailing days long before the weather forecast is reliable.
3) Setup. Can the boat be set up (from the trailer or cartop) by the number of people who will sail it - assuming one of them knows how to assemble it? Can this be done quickly enough to sail after work? If it is a singlehander - can you put it away alone in the dark?
4) Reliability and reparability. What is the mean time between failures that waste a good sailing day? If the boat gets holed by a floating log can I repair it myself?
5) Safety. Could the intended sailor be injured seriously as a result of the boat's design? Sure - some degree of risk may be accepted by the sailor. I would not want anyone to alter something that cripples to the performance of the boat just to make it safer, but don't build in booby traps.
6)Maintenance time to sailing time ratio. How many quality hours do I spend working on the boat versus sailing it?
7)Versatility. If the boat is designed for 2 can I still cruise with 3? Can I still sail it alone? Can the boat go racing one weekend and cruising with the kids and dog the next?
I want the fastest boat that is designed around these constraints, not some arbitrary number intended to limit performance but not cost.
