Over my 45 years of boating (sail and power) I have tried living aboard in
various climates and the dampness has always been a problem for myself and
my belongings.

I now live in the Pac. NW with a very damp climate and have found that good
insulation is very important to comfortable winter accommodations.

Just the first winter aboard my present boat, I found that the insulation
and cabin heat was still not enough to keep the damp out of my books,
clothing, bedding, food in cardboard boxes, etc. from molding.

Last winter I added a dehumidifier and I'm amazed at the difference it has
made. The uninsulated surface no long sweat driplets of water. It is still
important to have heat since the dehumidifier doesn't do well at low cabin
temp (50 deg.). The humidifier will remove about a gallon of water a day
if I'm constantly in and out of the boat all day. However, if I close boat
for a week or so, the humidity stablizes and the 2 gallon tank is only half
full when I open the boat again.

Admittedly, this dehumidifier is like having another person in the cabin,
but I have found a place for in the cabin and now find it a welcome
addition.

If I were to return to living aboard at anchor/mooring, I think the lack of
shore power and the dehumidifier would be missed most. Cabin heat can always
be supplied buy my faithful diesel galley stove but the humidity quickly
returns once the temp. drops and you open the hatch for a couple minutes.

Bottom line, don't move your book collection aboard until you are sure you
have the humidity under control.

--
My experience and opinion, FWIW
--
Steve
s/v Good Intentions