A Hudson River Gybe is a unique sailing maneuver that is only possible in a narrow set of conditions. When the wind is at the right angle, and the river is not too narrow, the captain can position the boom of the sail at a 90 degree angle from the keel. A change in wind forces the mainsail to switch sides, sometimes violently, to the other side.
Husdon River Sloops were designed as cargo ships that could pull tight turns in the narrow Hudson River highlands. Other cargo ships just couldn't risk turning close to a shore.
A Hudson River Gybe is especially dramatic when it occurs during the moment of silence aboard the Clearwater.
Further Reading
Hudson River Gybe - Clearwater Moment on Carl Carmer's description of a Hudson River gybe.
Physics of Sailing - Clearwater Moment on a captain's discovery through sailing.
Sailor Superstitions - Clearwater Moment on the curious superstitions aboard sailing vessels.
Come Sailing - Join us on board this Spring for a public sail!