I thought of various ways to keep a little air flowing through the main hull for ventilation and to keep the NC heat and humidity from creating a mildewy mess inside.
I saw these vents that were supposed to be used with boat covers on ebay. They come apart in two pieces and the boat cover fabric is supposed to be clamped in between, leaving the ventilating gap in the top half.
I bought a couple of them to experiment with (~$8.ea) . It looked like I could just screw the top part onto the bow hatch cover and it would have the same effect.
I didn't want to destroy my bow hatch cover in case it didn't work, so I bought a replacement cover so that I'd still have the original setup. Besides, when sailing, I would want it fully closed up anyway.
I didn't think to get any pictures until I was already done, so these are all I have (sorry).
I basically used 5200 to set the vent in through the hole drilled in the deck plate cover, and then put to stainless screws through it as well.
This is the cover installed.

Here is a picture of the deck vent and the "close-it-up" cover. The vent just screws out and the replacement put in.