Our forward berth portlights are clear, so they don't provide much privacy. There's also no way to shut out the sun in the morning and we didn't want to use curtains. We looked into some very expensive magnetic panels that go over the portlight, but decided to try a cheaper option for now. This film is made by Gila and it provides privacy, UV protection, and shuts direct light out. It also comes off pretty easily with a soapy solution. We're pretty happy with it so far. We like being able to see out of the portlights, so we probably won't do all of them, only selected ones throughout the boat.