Bought one pair from...
BoatUS to use as a pattern($$). I am sewing my own, pretty simple. You can buy the tracks, snaps, and snap tape(for sewing to the curtain) at BoatUS or West Marine. There is also a track that is just a narrow slot with little nylon slides. Then you make the curtain and use small drapery hooks to hook on the slides.BTW, I found the 8" x 20" to be too small. Recommend 12" x 20" but have no idea of the port size on your boat.