On Thu, 03 Jul 2008 14:34:39 -0100, David dh@. wrote:

I've got an old boat very much like this one:

http://www.warnersdock.com/images/Fr...fores15yel.JPG

that I'm trying to make into a mini-houseboat,
sort of like a camper. I only expect to have
about 200-300 pounds in the roof and walls,
and the roof will only be about 48" above
the gunwale. The hull will weigh a *lot* more
than what is added, so shouldn't that alone
be enough to keep it from being top heavy
and flipping over? If I add weight, like a
couple hundred pound bags of sand down
in the hull to counterballance, shouldn't
that take care of it? If so, should they
be placed on the sides, or in the center?

Use a tent! The thing will add only 20lbs to the boat, is easy to remove,
and can be configured all kinds of ways. Check LLBean for a tent that will
fit. Put a couple thermarest mattresses on the deck and you're good to go.