Yes, but as the overall displacement of the F18 hulls during a dive is ALSO much larger it NEEDS MORE STIFFNESS too. A F16 will typically sail with only 75% the displacement of a F18 [(107+143)kg/(180+15)kg]. Add to that the larger overall rig loads and the fact that it is wider and has longer hulls which both are providing for larger leverage and you'll see why putting F18 beams on a F16 are basically overkill.

For example, those 100 mm of extra width already makes the F18 platform flex 18% more even if it had the same weight and same hull length as the F16's. Now look at any 3.00 mtr wide Tornado or M20 and the flexing will go through the roof unless the beams are made very large. There are several of such factors that all need to be multiplied with eachother and that quickly adds up. That is also why going smaller (with teh F16's) was such a smart idea, because if going bigger and wider has such detrimental consequences then going small will result in equally large ... ... ...

You see, it is very dangerous to make conclusions about these things without doing the physical modelling. It is most definately dangerous to base any such conclusions on your gut (which many people seem to do anyway)

Some people even see proof for the benefits of stiffness in the very sharp feel of the Viper while sailing. It has a very crisp feel to it I'm sure. Sadly, the same comments are also made when such people test sail my own homebuild Taipan F16; and that one flexes 6 times more then the Viper ! Of course, even at that level its stiffness is (relatively speaking) better then any commercial F18 like the Tiger. Hence, I seriously doubt whether the Viper needs that much stiffness at all.

I forgot to give the Tornado flexing last time; it did 45 mm in the described test setup.

Wouter