The genoa or genny was originally referred to as an 'overlapping jib' and later as a Genoa jib, being named after the city of Genoa as explained below. It is a type of large jib or staysail that overlaps the main sail, sometimes eliminating it. It is used on single-masted sloopsand twin-masted boats such as yawls and ketches. Its larger surface area increases the speed of the craft in light to moderate winds; in high wind conditions a smaller jib is usually substituted, and downwind a spinnaker may be used. The feature that distinguishes a genoa from a working jib is that the former extends past the mast, overlapping the mainsail when viewed from the side.