Wouter,

The I-17R and NACRA F17 both have the 30' 4" mast. It's a cut down I-20 mast. I actually went and measured the cross section on an I-20 as compared to my mast. The I-17 " Normal " has the 29' mast.

I really don't believe they are making the F boats lighter, but I haven't seen or raced against a new F17.

Tom Turlington
Nacra F17/I17R