Hi Howard, Go read, and study Dennis............ He goes into great detail in winds from 0 to ? and tells you what sail to use; how it is adjusted; what to look for; why you are doing it, etc. .............including asymmetrical spinnakers, regular spinnakers, jibs, stay sails, all genoa sizes, (light air to heavy air), and mains............. He is covering all types of racing sailboats, from the smallest to the America's Cup boats. Find Dennis' book and your question probably will be answered by him. Connie