Those are not Nacra / Prindle innovations... but, Hobie has used mast step ball systems over the years on many models. We still do. I think the first was maybe the Monocat in the 70's?

Well, it was considered for the 16, but class rules and keeping it as one-design as possible won. Also, Hobie Cat USA (Dan Ketterman actually) came up with the "chip keeper". We also redesigned the stop thickness and refined the angles. We now see much less wear on all parts. We tested this out at the 2004 Hobie 16 Worlds. Never replaced a chip and saw very little wear to the stops. All in demanding conditions and time on the water that equaled a years use in just 10 days of heavy racing. We don't need no stinking balls!