Kneeboarding is a great sport. Essentially, the rider is strapped to a padded board on their knees, and then the rider holds on to a rope which is attached to the boat. What's the point you say? The point is to hold on, hit the boat wakes, get major air, and pull impressive stunts. Fun huh?
This is the one of the most extreme and painful water sports (in my opinion). Have you ever water skied? Well, picture doing it without skis. No matter what way you do it (off a boom, a 5' line, or long line) it hurts. Before I get up on my feet I have deal with an immense beating to my legs, back, butt, arms, etc. So why do it, you ask? I do it for the simple rush of skidding along the water at 30+ mph on my bare feet. It's the closest I'll ever get to walking on water...