Ketch mizzen sheet. So on a ketch, the dual purpose of the mizzen sail is to both propel and balance the vessel, while on a yawl, the smaller mizzen mainly serves the purpose of trim or balance. Yawls tend to have mainsails almost as large as those of comparable sloops. A ketch may be distinguished from a cutter or a sloop by virtue of having two masts rather than one, though a ketch with two foresails is sometimes called a "cutter-rigged ketch". Both the ketch and the yawl differ from the two-masted schooner, whose aft mainmast is taller than the foremast.
Ketch Sir Francis Chichester's earlier "Gypsy Moth" ketches had five staysails (each of almost equal size), none of which were boomed. If a ketch has no jibs, it is called a "cat ketch" or a "periauger". On older, larger ketches the main mast may in addition carry one or more square rigged topsails. The square-rigged ketch was largely supplanted by the brig, which differs from the ketch by having a forward mast smaller (or occasionally similar in size) than the after mast, and by the hoy, which was fore-and-aft rigged. Other similar craft include the snow and the pink. Both the