I installed a Northwater deck bag on my old Chesapeake Light Craft Tred Avon double kayak today. The bag has a folding Velcro panel that is intended to be secured over deck bungee cords or straps. I had my wife sew straps to this panel and then I screwed buckles to the deck. This provides an incredibly secure means of fastening the deck bag to the kayak. Check out this short video that shows the installation...