On Wed, 1 Apr 2009 18:43:05 +0200, "Edgar"
wrote:

To me, a swing keel is what the
deep ocean racers have, with a heavy bulb at the bottom that can be swung to
one side to provide better stiffness on a long tack.

No, what you describe is called a "canting keel", expensive and very
rare.

A swing keel is really a centerboard that pivots fore and aft.