Had the same problem with an old Necky Manitou 14. Upside down meant out of the boat. So I added thigh braces, and I ripped the seat back out and put in a backband that sits high enough to keep me in the boat inverted with moderate pressure on the footpegs. Suggest you ensure that your footpegs are close enough to you that you can put pressure on the thigh pads and backband, that you add padding to the thigh pads to keep your legs where they should be, and give you something to put leverage against, and that you get your backband high enough to have purchase on your hips, and not down around your butt cheeks...