Yeah 30+ feet. But I would learn backflips first for sure. The movements between them are easy enough to distinguish between. Think about this: When you're sitting on a floor, if you can roll backwards straight over your head, that's a backflip, compared to rolling back over one shoulder, which is the flat 3. To learn a backflip, I would first suggest trying them on a diving board. Stand with your back to the water, bounce once, then throw your body up and back. Have your arms out straight so that they are ~ 90 degrees from your starting position and parallel to the water. At this point, kick your knees up to your arms and tuck. It's very important that you dont bring your arms down to your knees, because you will backflop and be red and it'll hurt. Once you get those down, start throwing the backflip over one shoulder, then gradually tweak it more and more until you're fully off axis and flatspinning. Then you just have to put skis on and do it. No big deal.