The 3/16" inch seat is attached over the keel and under the sponson sleeves prior to inflation. When inflated, as seen above, the seat is held firmly in place by the sponsons. In addition, the inflated sponsons "trap" the side stringers to provide rigidity and shape. All 4 sponsons can be inflated in about 60 seconds. After inflation, the side brace tubes can be removed, one at a time, for loading of gear fore and aft. After loading gear, re-attach the side brace tubes.