powersloshin said..
so what's the difference between formula and slalom racing?
No real difference! The primary aim of the Foil race series is course racing (and marathon). We are discovering that racing is doable in light winds in a slalom type configuration when course racing is not really possible (due the lack of ability to make ground upwind). Beats sitting on the shore!

I reckon that foiling in the Slalom series will be conducted when the wind is stronger?