Karl,
Allowed and indeed available. The Stealth F16 (fully upgraded 2-up) is offered in full carbon mode. The version with half carbon hulls but carbon mast, carbon boom etc costs 10.350 GBP = 13.131 Euro's ex transport but incl. EU taxes. These two should balance one another for a person ordering from a low tax country. The single hander is cheaper at 11.200 Euro's
http://www.stealthmarine.co.ukIn fact remember this rule of thumb for the F16 rules. It does not rule on details only on an more abstract framework of dimensions that limit the performance of the boat by fixing energetic limits.
You can make an F16 from pure gold and platinum if you want but it won't be faster then a well made glass/alu boat. Compare it to gravity. A ball of lead falls just as fast as a ball of gold. Alot of classes try to achieve the same performance equalizing by limiting everything to be build from lead while simply limiting the shape of the balls and possibly the height of the fall is enough.
This is actually helping keeping F16 costs done, why pay more for a given performance then you have too ? Once you have hit the energetic limit, there is no justification for spending more apart from the Bling-factor. Personally, I think the F16's will end up using old tech were smart and only use the new stuff where it is most cost effective. Currently that means carbon daggers, rudders and stocks, some local carbon hull stiffenings and possibly a carbon mast but the rest will remain old tech as there is just not nearly enough in those other components.
That is the major difference of the F16 class compared to other classes. And up till now the results are excellent. The glass/alu 2-up (Blade) F16's (2nd) have proven again at this years Gobal Challenge to be just as competitive as the all carbon 1-up Stealth (1st) with only a single regatta point between them after 9 races.
Last years Global Challenge winner had a standard glass/alu VWM Blade F16 fitted with a carbon mast and carbon boom and spi pole. The second place belonged to the standard Alter Cup Blade F16 (glass/alu) and the champion lost out in the distance race to the Aussie Blade (Kevlar/alu)
But even more interesting is the fact that the carbon Stealth costs 13.130 Euro against the 14.500 Euro Blade due to company/labour force differences. For us it will be very silly to disallow carbon in the F16 class as our most inexpensive boat is mostly carbon ! We are currently the cheapest all out (meaning spi etc) racing class in the cat scene of today
Wouter