Hi Keith and Carol,
I fitted just such a hatch a few weeks ago since I was fed up with unmaking the bed to remove the log. I fitted a white plastic circular locker hatch (screw fit) after cutting through the bulkhead with a jig-saw. The hatch matches the one that provides access to the engine impeller on my Bavaria 33, but is a bit larger (maybe 12″ at a guess). Just enough light enters to see what I am doing, but a light would be useful.
Best regards,
Michael
(Vela)
PS/ I never have to clean the log since I remove it every time I leave the boat.