Here are some shots of the companionay hatch screens I made with some scrap Azek.

First shot looking out:



Second shot shows detail w/flash:



The top screen folds in half, so that the overhead hatch can close halfway in cases of inclement weather:



And the vertical pieces I made to the same dimensions as my hatchboards, so that I can use the solid top piece, allowing me to lock the boat up when I am away for the day, yet still provide lots more ventilation than otherwise (yes, locks keep honest people honest, and a slightly determined thief could get in if thy wanted, but it's a ventilation-vs-security tradeoff, and my marina is pretty safe, with 5 other liveaboards on my pier, someone is almost always around. )



External view of the screens: