Rolf,



May be another interesting question a la Scooby Simon can be formulated here :

Knowing that the M20 has a 20.71 sq. mtr. mainsail and a 25 sq. mtr. spinnaker, we determine its total sail area as just shy off 46 sq. mtr.

What would be the fastest design using the same platform and total sail area but unregulating the rig in any way ?



Many of us (including you) believe that luff length of the spi is much more important in performance then its actual area. May it be beneficial to keep the spi luff length but lower its area a little and use that amount to put a 25 % jib on the boat ?

Afterall a 5 sq. mtr. jib will only reduce the spi area by 20%.

Or better still. Reduce the mainsail area to 20 sq. mtr and give it an aspect ratio of 5 (same mast) and only reduce the spi by 4.3 sq.mtr (17% area reduction).

With the spi luff length unaltered this may only result in a very small performance loss on the downwind leg. Maybe even a negligiable one.

Of course the upwind speed will have been boosted by a larger amount leading to a nett performance gain. If this is the case then the uni-rig vs sloop rig debat for spinnaker boats under the assumption of same overall sail area will be over as well.


Have to go now, time to do some H_infinity controller design.

Wouter