A vessel having one mast and fore-and-aft rig, consisting of
   a boom-and-gaff mainsail, jibs, staysail, and gaff topsail. The typical
   sloop has a fixed bowsprit, topmast, and standing rigging, while those
   of a cutter are capable of being readily shifted. The sloop usually
   carries a centerboard, and depends for stability upon breadth of beam
   rather than depth of keel. The two types have rapidly approximated
   since 1880. One radical distinction is that a slop may carry a
   centerboard. See Cutter, and Illustration in Appendix.