Glossary

 A large heavy spinning rotor that is designed to precess (oscillate) in time with the wave-induced roll of the hull to create an opposing force that reduces the roll magnitude.  Therefore, improving the vessel's motion conditions for passengers and crew.

 A term that describes a blade mounted on the trailing edge of a foil or hull form.  The blade "intercepts" the water flow at approximately 90° to create a local dam to the water's flow, thus increasing the local water pressure and generating a lifting force that varies with the blade's depth of intrusion into the flow.

A symmetrical horizontally mounted foil designed to extend below the keel through attachment to a vertical strut such that the foil and strut combination form an inverted "T" shape.