We have a hatch dodger
we made for the forward hatch, built on a dorade principle, so that the hatch can be left open in the rain, too. I sewed it from the heavier weight stamoid (a pvc cloth), and we used old mainsail
battens for the spreaders. It has held up pretty well (I had to apply a couple of patches to an area that flexes a lot), for about 10 yrs.
You can work
it out logically, based on the hatch dimensions, and it works if you've a baby stay or a staysail stay to attach it forward. If not, I have seen "pram hood" arrangements used, also, that are free standing. We used press studs to secure it at the hatch base, and I used nylon webbing to reinforce the stamoid at those places.