I used a Beckson 6" screw in deck plate in the rear bulkhead of my Coho. It is watertight, quick & easy to install, and inexpensive. Unfortunately, it is also heavy and looks a little out of place on an otherwise all wood boat. It may also help to remember that the stated plate size reflects the size of the hole in the hatch - the actual dimensions of the deck plate assembly are about 1 - 1/4" larger in each dimension.