Forgive my innocence in this matter, but why do Nacra/HC need an additional 40 kg to build their hulls? For the sake of simplicity I assume the rigs of the F16 vs I17/FX1 have comparable mass, and in that case the 40 kg makes up about 30% (!!) of the total mass of the hulls. The weight saving may come from the use of newer materials (e.g. carbon fibre) or a different inner/support structure, but from some reading and talking to the salesmen this last weekend it seems as if the building principles and used material are very comparable. Is it so that the F16 boatbuilders just use less material and use it smarter (but if so how?) and are the boats from HC/Nacra in that sense just old-fashioned? Just curious / interested.
By the way: At the Nacra dealer I saw a 3D impression of the new Nacra F18 hull. It has the same 'negative' bow as the Blade and Fx One and is even more pleasing to the eye than the current Nacra F18 design.

Cheers, Bart