Marine Glossary

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A
Aft- The back of the boat; behind the mast.

Aground- When the hull or keel touches bottom.

Ahead- The front of the boat; Toward the front of the boat.

Ahull, Lying ahull- When all sails are lowered, usually in open water.

Alee- Away from the direction of the wind.

Aloft- In the rigging or up the mast.

Amidships- In the center of the boat.

Anemometer- An instrument that measures the velocity of the wind.

Angle of heel- The angle of a boat from the vertical, when sailing.

Apparent wind- The direction of the wind as it appears when the boat is moving. This varies with speed and direction of the boat.

Astern- To the rear of a boat.

Athwart- Across a boat; at right angles to the fore-and aft line.

Auxiliary- An engine used as a secondary source of propulsion.

B
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Back- To force a sail out against the wind. The wind backs when it shifts in a counterclockwise direction.

Backstays- Wires that lead from the top of the mast to the stern of a boat.

Backwind- A wind that shifts in a counterclockwise direction.

Ballast- Heavy material placed in the bottom of a boat to give stability.

Balloon jib-Sail used on a reach; larger and fuller than a genoa.

Bare poles- Having no sail raised..

Batten-A thin strip of wood or meatal placed on a pocket on the leech of a sail.

Beacon- A light, or other naviga-tion aid, usually on land, to warn boats of danger or obstruction.

Beam-The width of a boat at its widest point.

Beam sea- Waves running at right angles to the boat's corse.

Beam wind- A wind that blows at at right angles to a boat's course.

Bearing- Direction. To take bearings is to pinpoint the position of a boat on a chart, or in relationship to points on land.

Beat- To sail in the direction from which the wind is blowing. This requires tacking.

Beaufort scale- A table of wind velocity.

Before the wind- Sailing with the wind coming from behind.

Bell bouy- A buoy with a bell that sounds when the buoy is moved by the waves.

Below- Part of the boat that is under the deck.

Bend- To fasten by means of a knot.

Bight- A loop in a rope. Also a bend on a coastline.

Bilge- The lowest area in the hull, just above the keel.

Binnacle- The housing for a compass.

Bitter end- The end of a line or a rope.

Bobstays- Cables running form the bowsprit to the stem, near the waterline.

Bolt rope- The line sewn into the edge of a sail.

Boom- The bar to which the bottom, or foot, of the sail is attached. Boom jack is the tackle rigged to the boom to allow downward pressure.

Boot top- A stripe of paint applied to the hull at the waterline.

Bow- The front, or forward end, of a boat.

Bow line- A mooring line at the bow.

Bowline- A knot that forms a loop at the end of a rope.

Bowspirit- A spar, projecting from the bow, to which the jib stays are attached.

Bring about- To come around, to reverse direction.

Bring to- To stop the forward motion of a boat by heading directly into the wind.

Broach- To swing broadside to the wind when sailing downwind.

Broad reach- Sailing with the wind between the quarter and the beam.

Burdened vessel- Any boat that must give way to another having the right of way.

C
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Catamaran- A boat with twin hulls,

Centerboard- A device that acts as a keel in shallow-draft boats. It can be raised and lowered as necessary.

Chain plates- Metal plates attached to the side or the hull, to which the standing rigging is attached, stabilizing the mast.

Chart- A nautical map.

Cleat- A fitting for securing a line.

Clew- The corner of the sail where the foot meets the leech.

Close-haul- To sail as close to the direction of the wind as possible.

Clove hitch- A knot used for mooring a boat.

Come about- To bring the sail from one side of the boat to the other, when sailing into the wind, A maneuver in tacking.

Companionway- A stairway leading form deck to cabin.

Cutter- A sailboat with a single mast placed in the middle of the boat.

D
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Davits- A structure that projects over the side or rear of a boat used for raising and lowering a dinghy or small boat.

Day sailer- A boat that is not fitted for cruising over night. An open boat.

Deviation- Compass error caused by local magnetic attraction.

Dinghy- A small boat fitted with oars and sometimes sails.

Dismast- To remove a mast or masts. To lose a mast or masts at sea.

Displacement- The Weight, in tons, of the water displaced by the boat and its equipment.

Double-ender- A boat that is pointed at both bow and stern.

Downwind- Away from the direction the wind is coming from.

Draft- The depth of water required to float a boat. The depth of a boat from waterline to keel.

E
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Ease- To loosen. To let out the line of a sail.

Ensign- A flag identifying the nationality of a boat.

F
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Fall off- To head a boat away from the derection of the wind.

Fathom- A unit of measurement for water depth. One fathom is six feet.

Fender- Any material attached to the side of a boat used to prevent scraping when tied up.

Following sea- Waves that approach from the rear of a moving boat.

Foot- The bottom edge of a sail.

Fore- Toward the front of a boat.

Foredeck- The part of the deck of a boat that is toward the front.

Forestay- A wire or cable that runs from the mast to the bow of a boat.

Furl- To roll a sail up and secure it to yard or boom.

G
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Galley- A boat's kitchen.

Genoa- A large jib that overlaps the mainsail. It is controlled by sheets, of lines, that run outside the standing rigging. It is sometimes referred to as a jenny.

Gimbal- A device used to suspend equipment so that it remains level at all times.

Guy- A wire used as a support for booms, davits, etc.

H
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Halyard- Line used to raise or lower a sail.

Head- A ships toilet.

Heading- Direction in which a boat's bow is pointing.

Headsail- Any sail set forward of the foremast.

Heave to- To turn the bow of the boat into the wind and keep it there, so that the boat lies almost still.

Heel- The lateral tilting of a boat in motion, due to wind, sometimes to waves.

Helm- The rudder and the tiller or wheel, used to steer a boat.

Hoist- To haul up, to raise the sail.

Hold- The storage area below deck.

Hull- The body of the boat.

I
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In irons- The nose of the boat is directly in the wind and all forward motion has stopped.

J
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Jib- A triangular sail that is set before the foremast, that does not overlap the mainsail.

Jibe- To change direction in a boat in such a way that the wind passes behind the boat. Also Gibe.

Jib halyard- The line that raises and lowers the jib.

Jib sheet- The line that controls the jib.

K
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Keel- A weighted, projecting fin on the bottom of a boat, for stability.

Ketch- A two-masted boat, the smaller of the masts placed behind the larger, and in front of the stern post.

Knot- A unit of speed. One knot is one nautical mile per hour.

L
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Lanyard- A line used to secure a small object on a boat, or on a person.

Latitude- Position, in degrees, north and south of the Equator.

Lazarette- A small compartment for storing equipment.

League- Three nautical miles.

Leech- The after edge of a sail.

Leeward- Away from the wind.

Lie to- To head into the wind and stop forward motion.

Lifeline- A safety device that consists of lines on posts or stanchions around the deck of a boat.

Line- Any rope used on a boat.

List- Leaning to one side because of improperly balanced loads.

LOA- (length over all). Length of a boat at the longest measurement.

Log- A device, mounted under the stern of a boat, that measures speed.

Logbook- A boat's record of activity.

Longitude- Position, in degrees, east and west of Greenwich, England.

Loose-footed- Describing a headsail that is not attached to a boom.

Luff- The leading, or forward, edge of a sail. When this edge shakes in the wind, the sail is luffing.

Luff rope- Rope sewn into the luff of a sail.

LWL- Length of a boat at the waterline.

M
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Mainsail- The sail that is attached to main, or largest, mast of a boat.

Mainsheet- Line attached to the main boom that controls the mainsail.

Marlinspike- A pointed instrument used in splicing.

Mast- The vertical spar or pole supportiung boom and sails.

Mayday- From the French m'aidez, a distress signal.

Mean high water- The depth of the water at average high tide.

Mean low water- The depth of the water at average low tide.

Midships- The widest point on a boat.

Mile- A nautical mile is 6,080 feet.

Mizzen- Mizzenmast. The shorter, after mast on a boat.

Motor sailer- A boat that uses both sail and engine. The engine in these boats is larger that an auxiliary.

N
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Navigation lights- At sundown all boats in open water are required to carry lights. The system of lighting differs for each kind of boat.

Neap tide- The lowest tide in the lunar month. The high tides are lower than mean high, and the low tides are lower than mean low.

Nun- A cone shaped buoy, painted red, that is kept to the right side of a boat.

O
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On the beam- At right angles to a boat. On the bow is the angle from the bow to 45 degrees on either side. On the quarter is midway from beam to stern.

Outhaul- A line used to attach the end of a sail to the end of the boom, so that the sail can be adjusted.

P
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Painter- A line at the bow of a small boat for mooring.

Parachute- Balloon spinnaker.

Parallel rules- Two rulers, hinged together, that can be adjusted in distance while remaining parallel.

Parallels- Lines of latitude, north and south of the Equator.

Passage- A route between points or ports.

Pelorus- A special compass card used for taking bearings.

Pitch- The rhythmic bow- to- stern movement of the boat, due to waves.

Pitch-pole- To turn end over end.

Port- The left side of a boat, looking toward the bow.

Port tack- When the wind comes over the port side of a boat, and the sails are on the starboard side.

Prevailing winds- Average wind direction for season and area.

Privileged vessel- Boat that has the right of way.

Pulpit- A guard rail at the bow of a boat.

Q
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Quartering- Sailing with the wind between the stern and the beam.

R
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Reach- Any point of sailing between close- hauled and running.

Reef- To reduce the working area of a sail by lowering it part way.

Reef point- Small rope used in reefing. These ropes are attached at intervals across the sail.

Rigging- All lines, shrouds and stays on a boat that pertain to the sail and masts.

Rode- Line that attaches to an anchor.

Rudder- A device attached to a boat for steering. It is controlled by tiller or wheel.

Rules of the road- International regulations for boats.

Running lights- Lights required on all moving boats after sundown.

Running rigging- All lines, halyards and sheets used in controlling sails and spars.

S
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Schooner- A boat with two or more masts, the mainmast set aft the smaller mast(s).

Screw- Propeller.

Scupper- A drain hole in a rail or toe-rail or gunwale, allowing water to run off.

Seacock- A valve at a through-hull fitting, to allow intake of drainage of water.

Sextant- An instrument that determines altitude of sun and stars.

Sheet- A line used to control the trim of a sail.

Shorten- To reef a sail, or drop a sail. To reduce sail area on a boat.

Shroud- A wire cable used as standing or permanent, rigging to support the mast.

Single-handed- To sail alone; :without crew

Slip- A mooring at dock.

Sloop- a boat with a single mast set forward.

Sound- To measure the depth of water by means of a lead line or echo sounder.

Soundings- Depths as they appear on charts.

Spanker- A gaff-headed sail attached to the mizzenmast.

Spinnaker- A large, light triangular sail used in light airs.

Spinnaker pole- A spar or pole used to hold the spinnaker away from the mast.

Spitfire jib- A small strong storm.

Splice- To join two ropes or to make a permanent loop in a rope.

Spreader- A spar on the mast which holds the stays.

Spring lines- Mooring lines used to keep a boat from moving forward and back in slip.

Stanchion- A post or upright support for guard rail and lifelines.

Standing rigging- The shrouds and stays that support a mast; these are permanent fixtures while the mast is in place.

Starboard- The right side of the boat, facing the bow.

Starboard tack-Sailing with the wind coming from the starboard side, the sails on the port.

Stay- Cable or wire running from the mast to the bow or stern.

Staysail- A triangular sail set on a stay that runs behind the forestay.

Steerageway- Forward motion, allowing control of the tiller or wheel.

Stern- The after end of a boat.

Storm jib- A small, strong jib.

Storm sails- Small, strong sails for use in heavy weather.

Stow- To put something in it's place. To store.

T
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Tack- To sail to windward by alternating courses, staying as close to the wind as possible. To zigzag into the wind.

Telltale- Any lightweight device attached to mast or shrouds to indicate apparent wind.

Tenon- The bottom or heel of the mast that fits into the step.

Tiller- A bar connected to the rudder for steering.

Topping lift- A line that attaches the boom to the mast and takes the strain off the mainsail while it is lowered or set. Also a device used with a spinnaker.

Transom- The flat area of the hull, at the stern of a boat.

Trim- To adjust a sail by using the sheets to proper relationship with the wind.

Turnbuckle- A device for adjusting the tension on the shrouds and stays.

U
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Under bare poles- To have no sails up.

Under way- Moving.

Union jack- A small flag representing the nationality of the boat.

V
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Vane- A weathercock, A wind direction indicator.

Vang- A line used to stabilize the boom.

Veer- To change directions suddenly. To change direction clockwise.

W
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Waterline- The theoretical line on the hull where the boat meets the water.

Weather helm- A tendency to head into the wind.

Wheel- Steering mechanism.

Whisker pole- A pole attached to the mast, booming out the jib.

Winch- A device for hauling in lines.

Wing and wing- Having sails set on both sides of a boat.

Working sails- The sails used on a boat under ordinary conditions.

Y
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Yawl- a two-masted boat, with the smaller, after mast stepped behind the stern post.