Good to see you return, Frank! I always enjoyed your winter cruises, which I could do well from my warm and dry home.
I put one into one of my tanks last fall. On the side facing the engine room.
I used
https://www.seabuilt.com/contact.php
Installation was easy, the gasket and heavy ring on the inside and the panel on the outside. I needed to be able to reach in to clean and to repair, so used the one that allows a 12" hole. Did the trick.
I admit butterflies when I filled the tank again, relying on the access panel to be leak proof. It is, as least so far.
Installation was simple enough, a 1/2" drill to start a sawzall blade for the hole, a ring of 1/2" holes for the bolts, those are smaller, but are perfectly spaced. My ring of holes was imperfectly spaced, so the larger holes allowed for that imperfection. Once in place, the gasket and some thread sealer sealed it up.
What boat did you get? Will you be doing your winter in Desolation Sound and the Broughtons again?