Looks like starboard
 

Went out today on a lead for a hatch cover to fit over my gunnel, but the boat was gone. So it looks like a starboard hatch for me. The hatch itself is thin, but it looks like I would need to router out a good half inch for the hatch to fit over the lip. Thats if you want to call it a lip. So I guess I need a peice of 3/4 12x16, white in color.
Mike.