Unless you have a very heavy duty sewing machine, the proper needles, thread, material, and a bit of sewing knowledge it is not difficult, just time consuming because you don't have a pattern and need to make one. My boats are primarily aluminum walleye style fishing boats so the cover is designed to roll over the rail and snaps are placed on the bottom of the rail, not the side or top. Air cannot get under it from side. The windscreen is removable the cover is essentially flat except where it needs a slight pocket to fit the wheel. Since there is a trolling motor at the front, I made a pocket to cover it, only because it did not have a quick release. My other boats all had removable motors so this was not an issue. The nose bra was just that, a bra that covered much of the bow about 1/3 down and overlapped the cover at the top. No wind gets in, the cover cannot balloon. Do not use cheap grade vinyl. I used vinyl on two boats but it had a very thick backing and it worked nicely. Vinyl has a bit of "give" to it. There are other canvas type fabrics (Sunbrella) is just one. Look at the stitching on a store bought cover to give you an idea how the edges and seams are done.
