Increased windage is a factor, all testing and calculations indicates so. In the beginning (2001) the classic Tornado was still faster than the new rig Tornado upwind with the top Tornado teams sailing both boats. This was at the multihull evaluation event arranged by ISAF at the time and removed sailor skill quite well from the equation.

I just stalled a bit on the 3kg number as there must be a lot of intermittent steps between increased windage and calculated weight on the boat. That was all that was behind my question and it was not intended as a loaded question.

Dazz, only way I can see to do that would be two boat testing or some creative numbers games and a calculator. I guess it is more a question of feel and we certainly agreed when we switched from the classic to the modern Tornado. Going out on double trapeeze and trapeezing downwind more than made up for it in sailing pleasure we thought.


Greg, you are sailing under a yardstick system I guess. To stop people from removing their spi gear the day of the regatta everybody here have to declare at the time of signing up for the event wether they will sail with or without spi. If they dont say anything, it is assumed that they will sail with their boat set up like it is for the boats measurement certificate. This is enforced and if you race without spi, you are still scored as if you used the spi. I think that is a good system.
Even in light winds I much prefer sailing downwind with a spi compared to without