Ohh, my mistake !




If you want ? Of course !

Aspect ratio of the mainsail = 8.1^2/16 = 4.10
Aspect ratio F16's = 8.1^2/15 = 4.37
Aspect ratio F18's = 8.6^2/17 = 4.35
Aspect ratio A's = 8.8^2/13.95 = 5.55

But of more interest are the mast heights

iCat/FX-extreme/FX-one = 8.5 mtr
F16's = 8.5 mtr
F18's = 9.15 mtr
A-cats = 9.10 mtr

From an energetic point of view those 16 sq. mtr. of mainsail on a 8.5 mtr mast do not differ from the 15 sq. mtr. sailarea of the F16's on an equally tall mast. that is what the aspect ratio confirms.

Roughly speaking, both the iCat and F16's will milk the same body of air for energy and there is no reason to believe that the added sq.mtr. on the iCat will milk more. In fact, in lighter winds the airflow will stall more easily on the iCat sail and in big winds the added area will only require more depowering. I for one expect the iCat sail to be as good as the same in performance at both 16 and 15 sq. mtr. Which in my view makes the upgrade to 16 sq. mtr. (and non-F16 compliance) pretty useless.

With respect to CFRP hulls, if the iCat comes out at 220 lbs (ex spi) or higher then the use of carbon is questionable. F16's get down as low as 104 kg with plain alu tubes and GFRP. The added stiffness of the carbon in the hulls and beams will never amount to a significant performance difference. It will feel nicer but that is not the same as being faster.

But more interestingly look at the iCat pics (especially about the sterns):

http://www.hobie-cat.net/img/phototeque/icat/index.html

And then at the Falcon pics (or other F16)

http://www.falconmarinellc.com/falconf16.html


I will tell you where the major difference is between the iCat and the F16's. The iCat has about 230 mm longer sterns behind the rear beam. So making a F16 hull out of the iCat is pretty easy. Just insert a 230 long plug into the mould and move the stern 230 forward while fitting the same rudder stocks.

I've notices the same things when a F16 laid next to a Tiger or FX-one. The bows, the mainbeam location, stays etc are all in the same place. It is just the rearbeam location and the length of the sterns that are different. With regard to the FX-one the rearbeam was pretty much at the same location as the F16 and only the stern was longer by a 230 mm.

Since the keel line at the sterns is pretty horizontal anyway, you can just cut it away without upsetting the balance of the boat significantly. You are not really going to miss those 3 kg of bouyancy. Shifting your weight a little bit more forward will bring the boat back on its waterline again.

So, while trying to be really unbiased, I'm again amazed at how closely the iCat resembles the F16's. I truly amazed as to why Hobie Europe decided to go that route.

Wouter