on boats with only one jib, it is common for the clew of the jib to be further aft than the mast, meaning the jib and mainsail overlap. an overlapping jib is called a "genoa jib" or simply a genoa (see illustration). these are efficiently used when reaching more broadly than a close reach. alternatively, a boat may carry smaller jibs, to compensate aerodynamics when the mainsail is reefed; these more rugged sails are called "storm jibs" or "spitfires".