Interesting.
My first thought to the original post was that putting feet up on one
gunwale wouldn't change much - the centers of gravity and buoyance would
still be pretty much aligned.
If they were determined to cause the boat to tip, they'd have to stand up
and lean to cause the center of gravity to be outside the center of
bouyancy.
After reading your post, I suspect that they wouldn't all go overboard at
the same time, so I would expect the boat to right itself and not
necessarily ever take water over the gunwale.

"Doug Kanter" wrote in message
...
My (now ex-)wife, son and I took a canoe safety course a few years back.
The
instructor needed to teach us how to right a flipped canoe, so naturally,
we
had to flip it first. It took a concerted effort to do this. It's not as
easy as you think. 170 lb man, 150 lb woman, 75 lb kid - we had to start
the
thing rocking and then at the right moment, lean way over.

The same summer, I bought this stupid f**king rope ladder for my 14'
aluminum yacht, intended to help swimmers out of the water. Dumb ladder.
It
took two people *in* the boat to pull a swimmer out of the water. The
yacht
listed, the gunwale came within inches of the water, but the boat refused
to
go any further (not that we wanted it to). This was with me stepping on
the
stupid f**king rope ladder, and the other two right at the gunwale
offering
assistance.

Maybe a boat with more of a rounded bottom would tip, but I can only
relate
these two experiences. Now, if the water was colder and the spouses had
just
had an argument, everything might be different.

"K" wrote in message
link.net...
Hi. I'm looking to the experts (the boating experts, not the political
experts) for some technical help with a writing project I'm working on.
Say there's a small, open, no frills, 12 or 13 foot boat with an
outboard
motor. In the boat are two adults and their ten year-old son. Assume
that
the boat is sitting stationary in relatively calm waters (bay or
harbor),
and that there's no water inside the boat. How likely is it that the
three
of them might capsize it if they were to all simultaneously put a foot
up
on
the same side of the hull with most of their weight? Maybe they were
all
reaching out for something. Would they flip the whole thing over and
get
dumped in the water? Is that conceivable? Likely? Doubtful?
Any thoughts welcome.
Thanks...
-Ken