Does your camper get hot during the day in the summer? I went to a local camper store and bought one of the reflective window coverings, which just happened to be the same size as my sky light. Wal-Mart has 1/2 inch snap kits that are perfect. Install snaps all the way around the underside of the sky light and matching positions on the reflective cover. Using this cover has GREATLY reduced the run time of my air conditioner during the summer. Not to mention helps block light for those late morning risers...
www.huntwidow.net/sunshade.htm