What is the purpose of a spinnaker?

Question

What is the purpose of a spinnaker?

Answer 1

A spinnaker is the largest and most colorful of all the sail, it adds more speed to the sail boat, also a spinnaker is made of a different material than the other sail.

Answer 2

The spinnaker is a sail that is used only when the boat is sailing "off" the wind.  A 90 degree angle to wind would probably be the closest to the wind you could sail with a spinnaker.  This would depend on the wind velocity and type of boat.  When we race, we always drop the jib when the spinnaker is up.  This helps the spinnaker catch more wind.  The same boat at the same "off" the wind angle will almost always be faster with the spinnaker up as opposed to the jib.

The spinnaker does not have to be the biggest sail on the boat.  You could have 170% genoa and a smaller spinnaker.  Many spinnakers have bright colors and look like balloons when filled with air, but some are plain white.

Answer 3

It's the largest sail and is most useful when the yacht is running with the wind. It increases sail area greatly, hence wind gathered hence speed.