Large heavy duty rain cover for 3 seater swing seat, ?

Large heavy duty rain cover for 3 seater swing seat, other uses also. Similar to picture but my one is rectangle and does slope. This could also be used for other uses, such as patio furniture cover, motorbike cover, small boat cover. It is heavy duty waterproof nylon, , green in colour, and has rope at bottom to tighten it up, and keep it in place.Used twice and put away in garage. Sold seat so no longer any use for it,