<Dd> is the turning rotation of a vessel about its vertical / Z axis . An offset or deviation from normal on this axis is referred to as deviation or set . </Dd> <P> There are methods for both passive and active motion stabilization used in some designs . They include static hull features such as skegs and bilge keels, or active mechanical devices like counterweights, antiroll tanks and stabilizers . </P>

What does trim up mean on a boat