I'm still learning how to shoot this sport, to better anticipate the action and get the best shot instead of just shooting anything that moves! Practice, practice, practice!
The cool thing is that the kiteboarders have been pretty happy with my attempts so far, and I'm learning as I go along.
For this shoot I decided to try some changes, including moving to a shorter lens that has better focusing and sharpness characteristics and concentrating on closer-in action rather than the people who were dozens of yards away. So, the first of these pics were taken with the 100-400 lens, and then I switched to the 70-200 f/2.8 IS lens, which is one of Canon's sharpest. Every little bit helps!