2 yrs ago at a Class C I took a weird fall which took me a few weeks to figure out why it happened. 2nd pass 28 off 34 mph which I run 99.9% of the time, came around 4 ball in perfect position, but in the middle of the wake behind the boat my ski just seemed to stop dead, I went out the front, both feet ejected from the bindings, Connelly Visions. Did a couple front flips and ended up about 30' past 5 ball, totally bewildered. Ski was near the centerline of the course at least 50' from me. Swam back to shore but I knew my back was toast. Talked to some friends who saw the fall and they were also totally at a loss as to how it happened, said I was in perfect position out of 4 ball and the next thing they saw was me flying through the air. Bagged the next 2 rounds and drove home w 3 Motrins in me. Didn't ski for a week and a half, then just took a free ski up and down the lake. Got back to the dock and just happened to look at my ski, the fin had about a 1" section right on the bottom that obviously hit something really hard. It was flattened and the finish was gone, shiny metal showing with ridges on each side. Talked to another guy who had skied at the site where I took the fall and he said he has seen very large snapping turtles in the pond. My best guess is that I must have somehow hit one just under the surface at obviously a bad time. Had to replace the fin, not such a weird injury, just a weird way to get one.