Yes, that could hurt with the onboard supervision thing...
Laser, sunfish, butterfly & M-scow, VX-one, club/college 420, pretty much any multihull (wave on up).
They exclude sailboards, and kitesailors are under 10' so they're good.
I guess my sticking point is the sailing part of it. I understand the powerboating part, as that appears (at least to me) to carry the higher risk of injury/damage because they have higher speeds and range. But I see the argument could be made that I could sail a Wave to the Bahamas... if I had a deathwish.