I have seen a lot of Boats with Lace Doilys in the portholes. I can't crochet, and couldn't find 15 inch Doilys anywhere. I managed to find a 15 inch Quilt frame, similar to the hoops you use for embroidery. I bought two and because its a double hoop on each, they would do four portholes. I cut four circles out of some net and then stapled to the hoops. They look neat and tidy, don't block any light out and didn't cost the earth! Plus they give us a bit more privacy in daylight hours.