Flight Time wrote:
I'm no doctor, but I can't imagine kiteboarding is nearly as dangerous when it comes to broken bones as skateboarding. When it comes right down to it, I think water is softer than concrete, so I would give you the green light, but you listen to your dad. He has your best interest in mind.

I don't think the concern is about impacting and breaking bones. It's more of an issue with developing joints not being able to handle the strain.
There's a big debate on whether or not little league players should be allowed to throw curve balls. They can do it, but all that torque and strain on the kid's joints which aren't fully developed yet leads to long term injury.
Cameron, you've got plenty of years of kiting ahead of you. It's better to wait a few years now instead of risking joint problems your whole life because you just had to land that handlepass before your 11th birthday.

BTW, what is that green contraption you are riding in above? Is that a transmission on wheels powered by a lawnmower engine towing a wagon???