jybe v. 1. swing across boat: to make a fore-and-aft-sail swing across from one side of the boat to the other when sailing with the wind behind, or to swing across in this way. 2. change direction in sailing boat: to make a fore-and-aft rigged boat change direction by turning the stern across a following wind, or change direction by turning in this way. 3. n.  sail shift or direction change: a sudden shift of a sail back and forth or change in the direction a ship is sailing. 

keel n.  orig., the main longitudinal member of a hull; now, a similar shape molded in fiberglass. 

knot n. 1. a combination of loops and tucks that join a rope to other ropes or to objects. 2. a rate of speed of one nautical mile (6,076 feet) per hour. 

knotmeter n. an instrument for indicating speed through the water. 

lazyjacks n. light lines run between mast and boom to control the gaff and sail while being lowered. 

leach See leech . 

lee helm n.  the tendency of a sailboat to fall off the wind, requiring the helm (tiller) to be pushed to leeward to maintain course. S ee weather helm 

lee shore n. the shore on the lee side of a boat. The wind blows onto a lee shore. 

leech n. the after edge of a sail. 

leeward adj. in the direction of the lee side of a boat. 

lift n. 1. the forward-acting force generated by the airfoil shape of a sail . 2 . a similar force acting on the keel or centerboard 3. an advantageous shift in wind direction. 

luff n. the forward edge of the sail. v. to allow the wind to strike the leeward side of the sail. 

mainsail n. the sal located behind the main mast. 

mainsheet n. see sheet. 

make fast v.  to secure, as with a halyard, outhaul or any line. 

marline n. a light, tarred line used to whip rope ends, secure mast hoops to sails, etc. 

mast n. the vertical spar supporting the sail. 

mast rings or hoops n. sliding rings attaching the sail to the mast. 

mat n. a non-woven fiberglass fabric. 

on-the-wind n . sailing as close to the eye of the wind as possible. 

outhaul n. a line used to stretch the head or foot of the sail along the gaff or boom. 

parrel beads n. revolving hardwood beads strung on the line holding the gaff saddle to the mast. 

peak n. the top corner of a sail. 

peak halyard n. the halyard which hoists the outer end of the gaff on a gaff-rigged sail. 

pennant n. 1. a short line attached at one end, i.e. a centerboard pennant. 2. A long narrow flag. 

pintle n. the male half of a rudder pivot. See gudgeon. 

port n. 1. When facing forward, the side of the boat to your left. (Note: The terms left and right are used relative to a person; port and starboard are used relative to a vessel.) 2. An opening, such as the ports in the side of a cabin. 3. The shipping outlet of a city or place, a harbor. 

Porta Potti n. A trade name for a portable, self-contained toilet. 

Purchase n . A block and tackle with multiple passes of the line to give power ratio increase. 

Quarter n. the after corner of a boat. 

reef v. to shorten a sail, usually because of rising winds. n. a shortening of sail. 

reef knot n. a square knot or “shoelace knot” often with only one end looped for quick release. 

reef points n. small lines attached to cringles in the sail for gathering up excess sail when reefed. 

