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.