The calculators for both the Texel system (I made) and the ISAF small cat system are intended for small beach catamarans and I don't know how competable they are for the much bigger cat you talk about.



But the Calculators can be found here :



http://www.geocities.com/f16hpclass/F16HP_ratings.html



or



http://www.geocities.com/kustzeilen/ Under de header "home links"



Hope this helps;



Wouter