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On 24 Oct 2004 14:52:10 GMT, (William R.
Watt) vaguely proposed a theory
.......and in reply I say!:

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William R. Watt ) writes:

... what you usually see for boats is a graph
of righting moment against angle of heel. at some point there is a
maxiumum righting moment.

I think it should be clarified that the graph you see in the texts is an
abstraction and is not what happens on the water.

I think one I saw was real case.

On the water there are
more forces involved, especially on a mulithull. Take the extreme case of
a raft. One side is being raised through air while the other side is being
immersed in water. It's easy to push air aside but not water. As the raft
rotates there is a lot of turbulant drag around the side being pushed
through the water. There is a righting moment, but its not quite what is
calculated in the texts.

A cat is actually harder to tip than a barge, because weight, and more
importantly, buoyancy are at the extremes. With a barge, the water is
still pushing up under the middle of the vessel when it is quite
heeled. In fact it almost becomes a triangle as it tips.
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Have you noticed that people always run from what
they _need_ toward what they want?????