Your feet, your back foot especially, are probably going to move around a fair bit. I'd recommend not worrying about it too much. Try to be front on and your feet will follow.
Like graham said: At the moment you are using a side to side movemen to generate speed. You're hardly using the walls. Try going up and down the walls to generate speed instead.
Commented on Surfing StanceI'd like to get some op...
16 Apr 16:54
Your feet, your back foot especially, are probably going to move around a fair bit. I'd recommend not worrying about it too much. Try to be front on and your feet will follow.