I have shot a number of deer this way, including some decent bucks. It's quite a rush. Just like in a tree stand you need to be concerned about having decent cover behind you. The way you describe the setup, it sounds like it would be easy to spot you against the river so the camo material would be a good idea. I have a little chair that stabs into the ground on a spike. It keeps me low to the ground, which I think helps. I also wear Predator camo and hunt the wind. Knowing when to move is a big part of being successful. I generally don't try to build a blind or anything, I just sit by some brush or weeds and sit still at the right time and move at the right time.