This style camper hatch may put you in trouble for rot:

H Jim:

...all been tried (read my post on Page 1 near the bottom, outlining all my mitigation attempts).

Dan:

That looks interesting, and has several well thought-out anti-infiltration / exit features. I think if this style of hatch is non radius (non rounded corners), a size may be available to fit perhaps at least 1 opening in our camper...hmmmm?

The only thing worrying me is: I would have to saw into my composite walls to square out the 4 radius corners (this worries me a bit).