On Tue, 24 Mar 2009 17:02:21 -0800, "Calif Bill"
wrote:

Wonder if you could consider the wings that the America's Cup boats have on
the keel as an Active Variable Deadrise device?

Don't think so. The wings on AC boats were a rule beating device
which allowed the designer to increase the righting moment/stability
without exceeding the draft limit imposed by the 12 meter rule.

A lot of cruising boat builders thought if would be trendy if they
offered a wing keel also but then people found out what happens when
you run aground in a boat that increases its draft as you incline it.