I just started so I may still be doing things wrong, and I'm making the assumption that purposing is when the ski hops.
When I 1st started riding, I couldn't go very fast w/o it bouncing. As I have got better, I have got the least amount of hop while standing in the middle of the tray squated very low to let my knees take the force of the hop. I figure that right now I'm not skilled enough to use my weight to fight the hop, so I have been doing my best to take my weight out of the equasion. It has allowed me to run the ski full throttle, which I estimate to be close to 40mph. This is in 6" chop. I'm sure there are better ways and as I ride more I'll find something better.