Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. These are the results of the women''s 470 class competition in sailing at the 2004 Summer Olympics. Sailing is the art of controlling a boat with large (usually fabric) foils called sails. By changing the rigging, rudder, and sometimes the keel or centre board, a sailor manages the force of the wind on the sails in order to change the direction and speed of a boat. Mastery of the skill requires experience in varying wind and sea conditions, as well as knowledge concerning sailboats themselves.