When I leave the boat at the slip, I always look at the weather forecast to see whether or not I should leave the ports and hatch open for ventilation (I have not wanted to add any solar powered fan, or rain proof cowls, etc because of additional items on the deck to trip on). I've been looking for "something" to place on the open port windows that would allow air to circulate but keep rain out. The only thing I've come across is a permenant mounted rain shield by Beckson (http://www.beckson.com/irs.html). I don't like these because of the permenant mount which would also block the veiw/light. Has anyone seen anything similar to this but easily installed/removed?? I've considered having a plastics shop make one from the frame of the opening port window which has the plexiglass cut out and replaced by another piece that is slanted in on the top by about 2-3 inches with additional small triangular pieces on the sides (it would look like one of those plastic wall file folder holder). Once mounted to the open port using the latches/screw knobs it would keep rain out but still allow air in. Any thoughts on this idea...