i just typed this in a pm and i'm copy and pasting here>
well you need a riverboard, a riverboarding bungee, and a river. we do ours in a man made little ditch so its deep, perfect width, and such. you need something to tie the cord too and basically thats it. then you jump in and hold the cord. the current moves you down stream and at the same time it stretches out the bungee. while moving down stream you have to put the board on your feet and the current will push the board against your legs so it will stay there. you hold on in a "wakeboard position" until the bungee is fully extended. idk if you have wake boarded before, but you sit in the water with your chest facing up and your head looking forward. once it is fully stretched you move your legs at an angle where the board will be able to surface. so at a slight slant. without the full current pushing against the bottom, the cord and contract and it pulls you out of the water. it then flings you forward. the board is just like a skimboard so its like that. then you let go of the cord and cruissssee.