Well thought I would fill in another hole in the deck, ie. the hole just forward of the main hatch. It had a horrid plastic mushroom vent that was brittle and didn't take much effort to remove.  I have this lovely brass mushroom vent...

However, it needed a wooden Surround to mount it on and a similar piece of wood to finish it off inside.  I found a nice bit of teak and set about cutting out a circle with a hole to fit the mushroom vent.  Having a small lathe I decided to turn the wood and these are a few pics of me doing this.  I firstly made a disc the diameter I wanted then when happy with that. Started to cut the hole.  Had to be careful to tuen off the lathe once I had broken through.

 Result looks pretty good I think.  Now to fit it to the boat.

Pic of vent closed and open with teak base.

I was having second thoughts and thought maybe I should buy one of those solar powered vents and sell the bronze one to cover the cost.  What does anyone think?  The mushroom vent is fine but if I forget to close it and get one over the top I will get water below.  Whereas the solar vents allow air but no water to vent the cabin.  I would have liked one of the low profile cowl. Vents but they seem to be very expensive.

I have a smaller mushroom vent that I might fit on the stern to vent the rear lockers.