I did out of a 12 footer in the Brazos river. let me tell you.. it aint easy! I about fell out when I let the string go. In a way I'm glad I missed because if I had hit him and not sat down fast enough Id be willing to bet I was going in the water with him.
anyways don't let me discourage you. Get out there and try it. just be sure to bring a buddy with you to have a witness to all the goofy dance moves you'll be doing trying to get in position.