Buzzerbaby, I have used side planer in the river with not so good results yet. I know that this system will work very good given right water conditions. The slot that your talking about will probably be to fast for the side planer. What I have found in the past is that I can get the side planer to work great right on the inside edge of the seam. As soon as the planer hits faster water it will flip over on you and wash back and fourth. What I do to try and prevent this is to bring a couple of rubber bands and wrap the wire to the planer so it doesn't pop out when you hit faster water. I have had the planer all the way across the river before but it does take some work and right water conditions. Good luck and I hope this will help you! Fish on!!!