All of our boats have portholes. My 3500 has ten of them! For those of us who want to keep the sun off our woodwork--or want some privacy--there are few options. No one wants to drill holes to mount a curtain rod and curtains. Here is an easy, fast, elegant solution, but first, this is what I had when I bought the boat, which I was grateful for. They're more than some boats have:
I call them shower caps. They're okay, but labor-intensive and expensive to have made out of Sunbrella; and they're not exactly elegant, modern, or clean-looking.
Here is the solution you are going to thank me for. I saw this picture from a Pacific Seacraft and fell in love. (It pays to drool over other peoples' boats on yachtworld.com.)
First, go to a plastics retailer or find one online. You want 1/8" PVC foam board, such as this: http://www.eplastics.com/Plastic/pvc_foam_board
In San Diego we have a retailer called Ridout Plastic. I found PVC foam board in their scrap bin, so the amount I needed cost only $4.00. This material is great because it's stiff, light, opaque, and easy to work with. It can be cut with a table saw, Exacto/utility knife, tin snips, or very large scissors. It can be shaped easily by sanding and cleaned with soap and water.
Make a template of the glass portion of your portholes. I taped a large piece of paper over the porthole. Instead of using a pencil, I used a finger nail to trace the outline of the glass. This technique was more exact than using a pencil or pen.
I had two sizes of portholes and a total of ten. I used a table saw to cut the straight lines (top, bottom, sides) of each board, then I used the template and a french curve to cut the radii of the corners. This method will get you close, but not exact. On the boat, use some 150-grit sandpaper to fine-tune the fit.
You will also need 1/8" bungee cord and some wooden beads. West Marine had the bungee cord by the foot. I found these beads at a local specialty bead store.
If you don't want to search for beads, you can buy 12" sail tie-downs with ball ends (West Marine #159228), but they won't have the aesthetic of beads--and the size will not fit all portholes. You're better off custom-making the bungees.
It's interesting to note that the bungee cords and beads that hold the board in place do not have to be removed when you open the porthole. The bungee cord fits under the top hinges and there is plenty of room, so it doesn't interfere with the gasket. On the bottom, the cord fits under the C-shaped metal tab that is dogged down. Is there a name for this part?
Here is my end result:
I think it's a question of personal taste, but also utility. They're fast, effective, and appealing for a clean, modern look. Yes, maybe they're a little busy. I'll let you know after I've lived with them for six months. Regardless, they're far better than what a live-aboard at my marina said he and his wife use: paper towels and scotch tape. Yipes. Not on a Tartan!