Awesome pics! I like # 1 and # 4 the best and I think it's because of the moment you captured the subject - the body position had a level of balance with respect to the water and frame composition. Nice bokeh!
In general, I don't think people realize how tricky shots like these are - great job! I've been shooting motorcycle action for about 13 years now. Outdoors in the sunlight is very contrasty. Indoors in the fluorescent lights where arenas might use various bulbs with different color temps is also tricky. Adding windows for natural day light and a flash and I'll tell you, WB setting is nearly impossible to nail on the first shot. I find myself working on the PC doing a lot of pp for WB and since the lighting varies with different angles, I have to rely on the internal meter which isn't nearly as accurate as it should be for the price of the camera body alone.
Anyway, you've obviously got years of experience in photography. These turned out great and it looks like you lucked out a little with the angle of the diffused sunlight. It seems you had a partly cloudy day which helped too!