Lloyd Sumpter wrote:


People think that because water is "heavy" in air means that it's also
"heavy" (ie exerts a significant downward force) in water. This is simply
not the case.

True enough, but totally irrelevant. Which weighs more, a ton of feathers or a
ton of lead?

You are totally off base and your physics is wrong. Sorry to be so blunt. You
have no concept of what produces rightning moment; I suggest reading a good
simplified text on naval architecture, such as Robert Perry's book or Skene's
Elements of Yacht Design. Read the section on "metacentric height' two or
three times.

You point out that lead sinks and water does not. It seems to me that the
point is to increase stability of the boat, not to sink it. Wouldn't water
ballast be better, then?

If you like to paint imaginary scenarios illustrating how water functions as
ballast, then picture the following: a big ice chest full of cold beer. Take
it aboard your boat. The boat sinks a little deeper as the weight of the
cooler comes aboard, it's displacement has increased. In other words, the boat
is supporting the weight of that cooler & it's contents, wether those contents
are feathers or depleted uranium.

Now hoist that cooler to the top of the mast and try heeling the boat. Of
course, stability has been reduced, it will take less force to heel the boat
to any given angle. Now lower the cooler and place it as low as possible
against the bottom of the hull. Try heeling the boat again, of course you'll
find that stability has been improved. It will take more force to heel the
boat to any given angle.

Taa Daa!

A cooler full of ice & beer, which is absolutely lighter than water and does
not sink, has become ballast.

You're welcome.

Doug King