Although I can't find it in the class rules, I understand that the Isotope was grandfathered in (along with the Hobie 16 et. al.).
The hobie 16? That was never grandfathered into the class! Grandfathering is dependent on your local F16 association.
I believe that would allow you to sail an Isotope single-handed with main and jib (rather than gennaker). I haven't looked, but a jib might fall within the measurement rules of the gennaker as well.
No way. A jib is not a gennaker. The F16 box rules are really clear on what a gennaker is.
