Pascal, they are a lot bigger than they look in the picture. You can see the old small portlights to the right, that is the old center one. I thought you were doing the same thing. Plenty big enough to crawl through. Same hatches as used on the 80’s and 90’s cockpit motor yachts in the 65 to 80 foot range, they were mounted on the sides of the boats in the aft cabin. John