Hey Paul - I asked Jim Delozier, the dock designer at Wahoo Docks, and here's what he suggested: Have you considered using a pole & sleeve arrangement on your dock? With this setup the poles slide into the lake bottom and has the added benefit that coupled with winches on the sleeves the poles can be pulled up allowing the dock to be re-positioned. We use 4� schedule 40 poles with an angle cut on one end and cable running back up to a winch. The sleeves are 5� schedule 80 and are welded to our frame with mounting brackets for the winch.