Hatch is placed and sanded(“faired”).
After dry fitting the hatch I had to climb in a porthole in order to screw in the temporary side jams. It was a tight squeeze, but that was the idea behind the huge portholes.
Sand sand sand. Looks good.
Tsunamiball
Adventures in designing and building a tsunami-proof boat
Tsunamiball 
have you decided if you will make a hinge for it?
Eli, I definitely need to make hinges for the hatches. I like your recommendation of yoke hinges. I would do 2 for this back hatch, to increase the stability, yes? I’m thinking when the boat is in the water and the hatch is open, there is a good amount of stress on the hinges.
When I finish the hatch I can spec out the hydraulics as well. No reason to wait on the hinges, so I’ll give you a call to talk it through. Thanks.
Wow, the bottom photo makes the hatch opening look very wavy. It is dead straight. The wavy is an artifact of the iphone stitching together lots of little photos to make a guestimate at a wider angle single image. 😦