A sloop is a sailboat with a single mast[1] typically having only one headsail in front of the mast and one mainsail aft of (behind) the mast.[note 1] Such an arrangement is called a fore-and-aft rig, and can be rigged as a Bermuda rig with triangular sails fore and aft, or as a gaff-rig with triangular foresail(s) and a gaff rigged mainsail. Sailboats can be classified according to type of rig, and so a sailboat may be a sloop, catboat, cutter, ketch, yawl, or schooner.[2] A sloop usually has only one headsail, although an exception is the Friendship sloop, which is usually gaff-rigged with a bowsprit and multiple headsails.[3] If the vessel has two or more headsails, the term cutter may be used,[4] especially if the mast is stepped further towards the back of the boat.
When going before the wind, a sloop may carry a square-rigged topsail which will be hung from a topsail yard and be supported from below by a crossjack. This sail often has a large hollow foot, and this foot is sometimes filled with yet another quadrilateral square rigged sail called a "save-all topsail."[5]
The name originates from the Dutch sloep, which is related to the Old English slūpan, to glide.[6] In naval terminology, "sloop-of-war" refers to the purpose of the craft, rather than to the specific size or sail-plan, and thus a sloop should not be confused with a sloop-of-war.
After the cat rig which has only a single sail,[7] the Bermuda rig is the simplest sailing rig configurations. It is the most popular yacht rigging[8] because it is easier to sail with a smaller crew or even single-handed, it is cheaper since it has less hardware than more complex rigs, and it sails well into the wind. A limitation is that when a boat gets over 45 feet in length (approximately 13.7 meters), the sails become so large that they are difficult to handle,[7] although modern technology is helping with this through the use of electric winches and furling systems.
The headsail can be masthead-rigged or fractional-rigged. On a masthead-rigged sloop, the forestay (on which the headsail is carried) attaches at the top of the mast. On a fractional-rigged sloop, the forestay attaches to the mast at a point below the top. A sloop may use a bowsprit, a spar that projects forward from the bow.