I want to cover the companionway entrance to keep the cold air in when the AC is running while tied up at the dock and not have to bother taking the three slats in and out everytime we want to go thru. I saw a boat at a Marina once that had a flexible tinted sheet of plastic, like the windshield of a dodger. A trip to Lowes was unsuccesful at finding something like it. Any ideas out there? I was planning on using velcro to attach it to the inside lip of the sliding hatch and let it drape down the opening.