A spinnaker is a type of sail used on sailing boats, primarily designed for downwind sailing. It is larger and more balloon-like than other sails, allowing the boat to catch more wind and increase speed when sailing with the wind at its back. Spinnakers are typically made from lightweight materials to enhance performance. There are two main types of spinnakers: symmetrical and asymmetrical. The symmetrical spinnaker is shaped like a kite and is used with a pole to hold it out, while the asymmetrical spinnaker is designed to be flown without a pole and is easier to handle. Both types help sailors maximize their speed and efficiency on the water.