My pathfinder already integrates home made wooden hatches instead of plastic ones in the cockpit seat fronts however in this case, being the surface to keep dry vertical, the challenge is somewhat smaller as water will not normally sit around the opening.
In the case of the main twarth however things are diferent since the opening is cut on a horizontal surface where all sort of water would collect (splashes, rain water, condensation , ...) .
In my previous build (a SFD Stornoway 12) I had already integrated some plastic watertight rectangular hatches to provide confort and security, however I've hid them behind hinged wooden doors. The idea worked out well aesthetically however the implentation was slighlty flawed as water has nowhere to go once it finds its way easily past the non watertight wooden door and waits patiently to seep into the locker as soon as the plastic door is opened.
For the pathfinder therefore I applied a slightly improved solution where the unsightly (to myself) plastic hatches are integrated on a sloped panel built just underneath the main twarth ply surface. A wooden door is routed directly out of the main twarth so that once closed it covers the plastic hatch and matches perfectly the wooden grain of the surrounding surface (which will be the way finished in clear varnish).
The sloping panel helps preventing water to sit still around the plastic hatch door; standing water will drain by gravity through drilled holes directly into the cockpit area. A good solution? Only time will tell....