the columbus division had a demonstration set up at our annual Pet Expo... they invited me to bring my dog in to try it out (he would love it), but he was full coated (OES) at the time and it was about 30 degrees outside so I declined... they told me to look on that website for more info but there isn't anything i could find on joining a club or trying it out. I was a little sad about that, I don't let him do many dog sports because he is so large, and dock diving seemed like a lower impact for him. Plus - swimming!
Let me know if you find out anything more than I did. I was so frustrated at that website...