Simon,
The 1.067 number for Nacra Inter 17 (19m Spi), do you think it will be very different from what they are calling the F17?
Yes, VERY different.
From what I can gather (I still cannot get a measurement certificate for the boat, nearly 12 months after it raced at Carnac, I wonder why)!
My guesstimate is that the N17 in its current guise would rate around 1.02 on SCHRS (F18 is 1.005; Tornado 0.935).
THe N17 has larger sails and a longer mast than the EU inter 17 that the above rating comes from; we believe the hulls are lighter too.
But, without a measurement certificate, it's all guess work.
