I use burst mode with my camera frequently when I'm shooting the race car and at times like this when the boys are behind the boat. The 5D is a fast camera.
Split second action photography is not an easy task -- you often get the moment before or after you want. But with your camera, which is designed for professional use, it can be easier if you use your burst mode. Your burst mode fires repeatedly as you hold the shutter button down at three jpeg frames per second for up to 80 frames without stopping. I don't know how you made this shot, but it is excellent in terms of body language and expression and composition, a study in geometry. A gutsy shot, Jenene.