Open or close portlights?

[SeaRenity]

What is everyone's thoughts on keeping the portlights open or closed during the winter layup. With the boat shrinkwrapped I open all doors/drawers, stand up or take out all cushions and keep cabin entry door open. Would it be advisable to keep open the hull portals?
Thanks
Rich

 

[katricol]

I would keep one or two cracked.. Humidity is "relative" so I feel it will help

 

[Dancin Dave]

I would worry about critters getting in the boat through the portlites. Instead hang 6-8 damp rids through out the cabins.

 

[Warren]

I open the hatch in the forward head 4" and open the portlight in the aft head about 2" also - both with screens in. Then I prop all the doors open (with finders) about 10" for cross ventilation. No issues in 3 winters using shrink wrap (with plastic air vents in the film) for air circulation.
Warren