I usually use a 6x8 about 14 to 18" long if I am worried about sinking I place it on a pair of 2x8s or 3x 8s about 14 to 18" inches long. I lay them down next to one another and cross with the 6x8. They will not sink unless you are camping in a marsh. If height isn't an issue I would probably use an 18" 3x10 under each pad two with a cross piece the same dimention if I was worried with your rig. The out rigger pads are pretty expensive aren't they? I also Use a short boat hook about 3 or 4 foot,it works wonders for reaching things.