Glossary:  aka boat words for non-boaters
There will be a test in the morning.
Abaft : a seldom used expression for near or towards the stern, often from a given reference point, 'abaft the beam', meaning back from the beam
About : to change direction of the vessel by passing through the oncoming wind (tacking)
Adrift : not under sail or engine power, moving at the whim of the wind and sea
Aft : towards the back or rear of the boat
Aground : stuck on the ground, a mud bank, sand bar, or worse (rocks or coral)
Ahead : to go forwards
Aloft : anything above the deck and cabin, to go up the mast/into the rigging
Anchor : a heavy metal ‘claw’ designed to grab hold of the sea floor and keep a boat from moving
Anchorage : a place protected from wind and waves, with bottom conditions suitable for anchoring
Apparent wind : combines both the true wind direction and the boat's speed and direction
Astern : pass to the rear of a boat, as in to 'go astern' meaning to go behind the boat
Autopilot : a computer-controlled mechanical or hydraulic-powered device to steer the vessel. Often connected to a chart plotter
Avast : To cease and desist. 'Avast there, mates,’ if said with a pirate accent, means 'stop screwing around, guys.'
Backstay : the wire cable running from the back of the boat (stern) to the top of the mast
Batten : a wood or fiberglass strip inserted through the leech of a sail, sometimes extending as far as the luff, to improve sail shape, support the leech, and prevent fluttering.
Beaufort Scale : a 0-12 scale of wind strengths (calm through hurricane) and identifying characteristics. For example, 6 is a strong breeze, 24-31 mph or 21 to 27 knots. Expect to see long waves with foamy crests and some spray.
Beam : the width of the boat, or a direction, as in 'off the beam' meaning perpendicular to the vessel. Replaces athwart
Bearing : the direction to something, usually relative to the boat or a chart
Bear away : to turn away from the current direction usually with respect to the direction of the wind, also 'bear off.'
Beating : to sail as close to the wind as possible
Becalmed : when the vessel is motionless because of lack of wind
Below : under the deck, as in 'to go below'
Berth : a nautical bed, usually narrow, sometimes wet. The expression 'to give a wide berth' is not about a captain's generous berth allocation, but to avoid something (another vessel) by a wide margin. Also, berth refers to where a vessel is normally docked.
Bilge : the part where the side of the boat turns into the bottom of the boat, also the bottom of the boat where smelly water gathers
Bimini : a sun cover of canvas stretched over the cockpit, and supported by a metal frame
Binnacle : a stand or support for the ship's compass
Bitter end : the last part of a line or anchor rode
Boat hook : a sometimes-extensible pole with a hook in the end to catch things like mooring lines and hats when they drop in the water
Bobstay : a wire running from the bow to the end of the bowsprit to relieve the load from the forestay
Bollard : a hefty short post typically attached to the dock. Used to secure boats
Boom : the stick attached near the bottom of the mast allowing the sail to pivot with the wind
Boom vang : a system of ropes and pulleys,, or a springloaded rod, to stop the boom from lifting up
Bosun's chair : a canvas seat used to hoist crew up the mast to make repairs
Bow : the front part of the boat
Bowline : a temporary knot, easy to tie, and untie after being loaded. See http://
Bow line : the rope connecting the bow to the dock
Bowsprit : the ‘stick’ extending from the bow, allowing the boat to carry more sail, not be confused with the anchor roller
Bridge : the elevated position from which a boat is steered, or an overhead structure requiring care to go under
Broach : when large waves and/or strong wind cause a vessel to lose control and turn sideways, often heeling dramatically, with a chance of rolling over
Bulkhead : a vertical partition in the cabin providing stiffening/watertight compartments for the hull
Buoy : a float used to mark a position or thing
By and large : a common expression of nautical origin, meaning a vessel performs well going into the wind (by) and with the wind (large), so all possible points of sail.
Capsize : to turn the boat over by 90 degrees, or more. Not recommended!
Cast off : to let go mooring or dock lines so the boat is free to move
Catamaran :a boat with two hulls side by side
Chaffing : wearing of lines against things causes them to fray and eventual fail. Prevented by chaffing gear, for example, covering the affected part with hose or leather
Chart : a map used on a boat, showing details of the coast and what is under the surface
Chart plotter : an integrated computer/monitor that presents navigation charts and the vessel's location. Enables courses to be plotted as routes, or tracking of the vessel's movements
Cleat : a fitting for preventing ropes from moving. For example, a dock cleat
Clew : the corner of a sail furthest from the bow
Close-hauled : to sail as close to the wind as possible. Requires hauling the sails in tightly
Coach house : part of the cabin projecting above the deck, often with larger windows
Cockpit : a somewhat protected area for sitting and steering, usually lower than the deck
Come about : to change direction by passing through the wind
Companionway : the entrance to the cabin, usually as stairs from the cockpit
Constant bearing-decreasing range: (CBDR) occurs when one vessel maintains a constant bearing relative to another vessel, while the distance between them (range) decreases. This is a collision course.
Course : the direction that is a boat is to be steered. Course over ground (COG) is the actual course after including the effect of wind, tide, and current
Current : a flow of water from one area to another (not a tide, where the water flows back)
Cutter : a single-masted boat with two jibs. Also a fast motor boat often used by the Coastguard
Davits : a small crane or spar used to lift things, such as a dinghy or outboard motor
Dead ahead : directly in front
Dead reckoning : is the process of using estimates of direction and distance traveled,and sightings of landmarks to determine a vessel’s position
Dinghy : a small open boat. Some dinghies can be inflated
Dock : a place to tie up a boat for a period of time and walk on dry land , also a pier or wharf
Dodger : a see-through screen and hood at the front of the cockpit to deflect wind and waves
Draft : the minimum depth of water a boat requires in order to float
Drogue or sea -anchor is a device towed through the water to slow down a vessel. Can be a parachute, a long length of rope, a large cone, or a series of small cones attached to a long line.
Fathom : six feet
Fender : an inflated cushion between boats, or a boat and the dock to prevent damage to the hull
Fiberglass :a durable, strong composite of polyester resin and layers of cloth made from glass fibers. Used for the vast majority of boats manufactured since the 1950s
First rate : an expression derived from the top-of-the-line sailing warships (100 guns) from the 1600s through 1800s
Flare : a pyrotechnic/firework, either hand-held or fired from a gun to draw attention to a vessel in distress
Following sea : waves from astern, going in the same direction. Under certain conditions the vessel can surf the wave, picking up considerable speed and a chance of losing control. Waves that overtake the boat can be especially dangerous if the wave is breaking.
Foot : the bottom of a sail
Fore : forward or front, as in fore-deck and fore-peak, the cabin squashed into the bow
Forestay : the wire cable from the top of the mast to the front of the boat
Forward : toward the front of the boat, as in “Go forward and drop the anchor.”
Frames : ribs that form the hull’s shape, typically used in wooden boats
Furl : to reduce a sail’s area. Jibs and genoas are typically wound around the forestay. In a similar fashion, mainsails may be furled inside/outside the mast, or inside the boom. The alternative to storing the mainsail is along the boom by folding the sailcloth.
Gaff : an oblique stick attached near the top of the mast. Used to hold the top of a four-sided sail, while allowing it to pivot with the wind direction. Also a pole with a sharp hook on the end to assist in bring fish aboard
Galley : the kitchen in a boat
Genoa : a large, powerful jib overlapping the mainsail
Gooseneck : a fitting connecting the mast and boom, allowing the later to swivel
Grounding : an ill-advised contact between the boat's hull or keel and the bottom (ground). Also used in lieu of 'bonding', a process of electrically connecting all metal (engine, thru-hulls, etc) and the top of the mast to minimize damage in the event of a lightning strike
Gunwale : the edge of the side of the boat and the deck
Gybe : the process of changing course and/or repositioning the sails from one side of the boat to the other with the wind coming over the stern. A dangerous maneuver if the wind is blowing hard
Halyards : ‘ropes’ used to hoist and lower sails
Hank : a metal or plastic hook/device to connect a sail to a mast track or forestay
Hatch : an opening in the deck or cabin roof to allow light and fresh air to enter
Head : the top corner of a sail, also a nautical toilet
Heading : the direction the boat is going in, to head up is to sail closer to the wind or into the wind
Heave to : to stop the vessel by sheeting the jib to one side and locking the rudder in the opposing direction
Heel : leaning sideways of the vessel induced by the wind's sideways force on the sails
Helm : the steering wheel, as in the command ‘take the helm’
Jackline : a continuous line running from the bow to the stern for crew to clip on to when moving about on deck. Essential when conditions are dangerous and there is a risk of falling overboard
Jetty : a stone wall projecting from the shore to protect boats in a harbor, also a quay
Jib : a triangular sail in front of the mast, with one side usually connected to the forestay
Jury rig : using whatever is at hand to make a temporary rig in the event of dismasting
Keel : the very bottom of the boat, usually cast of lead in a sailing boat to keep it upright
Ketch : a vessel with two masts, the tallest one in front and a shorter one behind
Knot : a speed equal to one nautical mile per hour (1.15 mph or 1.85 kilometers per hour)
Latitude : a geographic coordinate (distance) measured in degrees north/south (up to 90o) of the equator (0 degrees)
Lazy jacks : ‘ropes’ from the mast to the boom to keep a sail from falling to the side
Leech : the aft or trailing edge of a sail
Lee : the side sheltered from the wind, leeward is the direction away from the wind. A lee shore is on the side of the vessel opposite the wind. Being blown on to a lee shore during a storm is a good reason to be safely tied up at dock, or a long way offshore
Life raft : an inflatable covered raft used as a last resort when the vessel sinks
Line (s) : there are no ‘ropes’ used on a boat. They are lines, unless specifically purposed as halyards, sheets, outhauls, downhauls, boom vangs, etc. Also see ‘rode.’
Log : a record of a boat’s operation with courses and events, also a device to measure speed
Longitude : a geographic coordinate (distance) measured in degrees east (up to +180 degrees) or west (up to -180 degrees) of the Greenwich meridian (0 degrees).
Luff : the forward edge of a sail, also to head into the wind until the sails invert in shape and flap, sometimes very loudly
Lying ahull : with sails removed, the vessel rides out a storm at the mercy of the sea while the crew cowers below
Mainmast : the tallest mast
Mainsail : the primary sail attached to the mainmast
Mainsheet : line used to haul in the boom to adjust the sail's shape to wind conditions and direction
Mizzen : (mast or sail) the mast or sail closest to the stern
Mooring : attaching a boat to a sunken weight, or a dock
Nautical mile : approximately one minute of latitude, or 6076 feet, 1.15 land miles, or 1.85 kilometers. Note that definitions of length vary. For example, the American Practical Navigator defines a sea mile as an “approximate mean value” of “6,080 feet; the length of a minute of arc along the meridian at latitude 48°.”
Navigation : the process of way finding the current position and conducting a boat from one place to another
Oar : a rowing device connected to a dinghy and used to move it (not a paddle)
Outboard : a detachable gasoline-powered motor mounted on the stern
Painter : a line attached to the bow of a dinghy for tying up or towing
Pier : a dock extending out from the shore
Piling : a wood (or concrete/steel) pole driven into the bottom
Pitch : the bow-to-stern up and down movement of the boat caused by waves
Plane : when a boat lifts onto the surface of the water, rather than pushing through it. Most sailboats are displacement vessels, meaning they displace their weight in water and do not plane.
Port : the left side, identified with a red light at night. Also a harbor, a nautical destination
Portlight : a waterproof window in the side of the cabin
Pulpit : a safety railing at the bow, made of metal pipes
Reaching : to sail with the wind off the beam, (ranging from 60 degrees to 160 degrees). A close reach has the wind forward of the beam, while a broad reach has the wind aft of the beam
Reef : to reduce sail area by lowering the sail and tying up what is not used
Rigging : the various lines, stays, and shrouds needed to support the mast and operate the sails
Rode : the anchor rope or chain
Roller reefing : used to reduce the sail area by winding it around the mast or boom
Rudder : the board attached to the steering wheel or tiller which causes the boat to change course
Run : to allow a line to move freely, also a direction of sail, such as running before the wind.
Running backstay : is an adjustable wire used to hold the mast from the rear, employed during severe wind conditions
Safety harness : a harness made of webbing (or incorporated into a life jacket) enabling a crew member to be secured to the vessel during hazardous conditions
Schooner : a sailing boat with two masts, the mainmast behind the first or foremast
Scupper : a drain from the cockpit, or to enable water to leave the deck through the gunwale
Sea anchor : see drogue
Seat locker : a locker under the seats in the cockpit
Seacock : a shut-off valve below the waterline; sometimes mistakenly called a thru-hull, which refers to a mushroom-shaped fitting penetrating the hull, and attached to a seacock
Secure : to make fast
Seasickness : motion sickness caused by the rocking action of the boat going through waves. The primary symptom is nausea, aka puking one’s guts out.
Self-steering : a mechanical system of levers , gears,and wind vane to make course corrections via the rudder so that the vessel maintains a constant relationship to wind direction
Sheets : ‘ropes’ used to control the angle and fullness of the sail, attached to the jib clew, the bottom corners of a spinnaker, or the end/middle of a boom
Shroud : a wire connecting the top of the mast with the side of the boat. There may be several shrouds per side
Slack : the opposite of secure, something not secured, to loosen. Also slack tide
Sloop : a boat with a single mast, one jib, and a mainsail
Spinnaker : a large, lightweight, usually colorful sail used when the wind is coming from astern to off the beam (perpendicular to the vessel)
Spring line : a line usually from the middle of the boat to a forward or aft dock cleat
Stay : a supporting wire connecting the mast to the bow (forestay) or stern (backstay)
Staysail : a sail fixed to a stay, for example, a cutter rig has an outer jib and a smaller jib attached to an inner forestay
Squall : a violent wind that arrives suddenly, often with rain
SSB Radio : single-sideband modulation radio similar to Ham radio, used for medium to long-range marine communications with fixed channels and frequency selection. Range depends on environmental/atmospheric conditions.
Stanchions : metal pipes secured to the gunwale holding lifelines to prevent crew from falling overboard
Starboard : the right side of the boat, associated with green (e.g. lights and buoys)
Stern : the rear of the boat
Stern line : a rope used to tie the rear of the boat to the dock
Storm sails : very rugged small sails (storm jib and a trysail) used to replace larger sails in the event that severe winds make reefing or furling insufficient.
Stow : to put things in their proper place. ‘Stow it’ is rude expression comparable to ‘shut up’ or ‘get over it.’
Tack : the bottom, forward corner of a sail, also changing direction when going into the wind
Tide : a periodic rise and fall in water caused by the gravitational pull of the sun and moon and the rotation of the earth. Tides vary by location, ranging from a few inches in lakes to many feet.
Tiller : a handle attached to a rudder or outboard motor to enable steering
Trim : the balance of a boat achieved by distributing the weight fore and aft. Also to adjust the shape of the sails for better performance
VHF Radio : very high frequency radio (marine application broadcasts in the 156.0 and 162.025 MHz range) with international-standard channels. For example, 16 is the hailing and distress channel. The range is ‘line-of-sight’ and varies depending on signal strength, antenna, environmental conditions, and obstructions. US Coastguard transmissions exceed 60 miles, while a typical sailboat range is between 10 and 30 miles.
Wake : the disturbance of water caused by a boat’s movement
Winch : a metal drum turned by ratcheting gears and a handle to give leverage, used to hoist or pull in the sails
Windlass : an electrically powered device for raising the anchor
Windward : the direction the wind is coming from
Yawl : a two-masted vessel, the mizzen mast being much smaller and farther aft than that of a ketch