How much Flotation? And Where?

David Kautz (
Tue, 04 May 1999 09:55:45 -0700

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West Wight Potter Website at URL
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After reading Bernie's comprehensive list of improvements he'd like to
make, several of which involved adding flotation, I found myself with a
couple questions that I couldn't answer:

Question #1: How much floatation is enough? Once there is adequate
floataion aboard to keep the boat from sinking and being lost, what is
the benefit of more? I don't see how any amount of flotation will
PREVENT a capsize or change the stability curves of a boat before it is

Question #2: If a boat had a lot of addtional flotation, particularly
low in the boat as in the bilges and under the cockpit floor (places
where Bernie is proposing to add it), could that make the boat MORE
prone to turtling and more difficult to right once inverted. It seems to
me that if the boat was on it's side and was entering the cabin,
flotation in the bottom of the boat would actually _encourage_ the boat
to continue over into the inverted position whereupon the flotation
would make it very stable upside down.

Would it be wiser to place flotation high in the boat, like behind the
cockpit seat backs to encourage a "right side up" attitude?

I'd be interested in hearing the thoughts of others on this. Most of the
times I've thought of "improving" my P-15 I've gone full circle and come
to the conclusion that both Stanley Smith and Herb Stewart were smart
guys who put a lot of thought and calculation into their designs and
that my "ideas" were not "improvements" after all....

Dave Kautz
P-15 #1632 Tilly Lucy
Palo Alto, CA