raleys: learning boat speed/rope length

I tried my first few raleys Sunday. The first two I stargazed, landed turned switch toward the boat, and fell on my butt. The third one I put more wieght on my front foot, landed turned regular toward the boat, caught my heel edge and got thrown down hard.

I ride at 22mph on a 70 foot rope. Its is easer to learn this trick at a lower speed and shorter rope? Maybe 20mph @ 65ft?