Maurizio,



I agree with alot but please, we shouldn't over do it. Or make it into more than it really is.



>>Anyway yr "UNDERPOWERED" F18HT is faster than any other 20 footer both upwind and downwind up to Force 3-4.



I would like to distance myself (and the F16HP class with it) from claims like this. A US I-20 has nearly the same mainsail as the F18 HT and is equally high and together with the slot effect the I-20 rig will produce more power than is proportional than it's increased draq. Ergo it has a better power to drag ratio.



Now I might accept downwind but not upwind. Simply because in a few examples the numbers just don't add up.



>>>The INTER 20, HOBIE FOX, NACRA 6.0 etc. are slower in all conditions than F18HT cats.



This is a tough claim. And I don't think that the situation is that clear cut. But time will tell.



>>The reason:

LESS WEIGHT (110-130 lbs), LESS POWER (204 sqft against 225-245 sqft), MORE EFFICIENCY (UNIRIG vs SLOOP - higher aspect sailplan/32' vs 29.5' tall mast)



More efficient ? This is very simple to say but equaly hard to proof scientifically. I can assure you that efficiency in this respect is very dependend on conditions. A sloop in higher winds of equal or little less overall sail area can well produce more thrust than a high masted uni rig that is depowered under the same conditions.



These numbers and remarkable meteological phenomenons favour the F18HT heavily in winds up to 5 kns as well as any other high masted rig. But right from 6 kns and up the advantage has been cut down to just a few % ; this is without depowering, when the rigs get depowered the sloop will close the cap even more and even overtake the uni rig in total produced power.



These numbers do explain the F18 to iF20 experiences in the medd to high winds so why shouldn't they cover the F18 HT.



Now saying that the F18 HT is much faster than all others can do us far more damage than we want inflict on this new lightweight classes. So please, do not overstate the performance.



Once again, F16 HP class does not support these claims and my models who have been used to develop this clear don't do so either.



Wouter