A SPINNAKER is a large triangular sail used in sailing. It is designed to capture the wind and provide additional speed and maneuverability to a sailboat. The SPINNAKER is typically flown from the bow of the boat and is often brightly colored. It is usually made from lightweight materials such as nylon or polyester, and is designed to be easily handled by one or two people. The SPINNAKER is an essential part of sailing and is used in both racing and recreational sailing.