Geert,

I have raced as a crew on 44 and 48 foot Cabin cruiser Cat for the last three years. The build up hulls (accomodation) and the roofed Salon mid deck on those boats present a HUGE frontal area and indeed lead to significant windage.

But I have never seen these features on a beach cat. In fact the Miss Nylex C-class design reflects today's beach cat design alot more closely then the DOGstar 50 if you ask me. If the total windage of everything is given as 4% there then I think that would be the best place to start for us Beachcats as well

Best of luck,

Wouter