Thanks for the info!
I will go with the polyester then, as the main concern is UV stability.
Second are clearness of the coat/layer and adhesion to wood and the
fiberglass (polyester, I assume) of the hatch. Strength is not an
issue, none of this is structural.
Any concerns with that from anyone? (Double-checking before I putting
sticky non removable stuff on large visible parts of the boat.
Thanks!