"Witzgall - the forward hatch in the picture is going to break or develop a severe leak quickly."
Well there's a statement that i completely disagree with. The majority of production boats have their forward hatches
mounted with the hinges
aft and they rarely, if ever have a problem. The dog side of the hatch
side) usually has the better seal since the dogs compress the gasket making a forward facing hatch
more watertight when hit with green water (half blue-half yellow) when closed. An open forward hatch will catch jibsheets whichever way it faces.
In terms of ventilation, I had a boat which had a forward hatch that could open either way (you shifted the hinge
pins) and it clearly had better ventilation when opened to the rear. There is a theory of ventilation that suggests that the area of the exhaust
end of a non-compressed ventilation system should have 50% more area than the intake end. On my boat the forward hatch has its hinges
facing aft (opening facing forward) and the main cabintop mounted hatch has its hinges facing forward (opening facing aft) which when combined with the area of the companionway seems to be consistent with that theory.
I do leave the midships hatch with the forward hinges open when sailing in moderate or less conditions and it does not seem to take spray down below.