I made a new Surfski bag using my sailrite lsz1 sewing machine. The one I replaced was the very first thing I'd ever sewn using cheap nylon fabric from Jo-Ann Fabrics. This time I used Sunbrella and PTFE thread with a lifetime warranty. Also, this time around I sewed the zipper to run along the bottom of the boat. All the commercial ones, like these , have the zipper on top. Hopefully i don't regret this, but it makes more sense to me to have the zipper on the bottom. You lay the surfski on the stands so it's off the ground, roll out the cover on top, then pull the zipper underneath the boat, lifting it as needed to get over the stands. My surfski only weighs 35lbs, so it's easy to lift. So far having the zipper along the bottom works great, but you do need the stands. If water gets into the bag when driving through rain, the water can now drain out via the zipper along the bottom. The con is you need stands and long monkey arms like mine, but ...