Are you a new boat owner? Whether you bought a jet ski or a 40-foot cabin cruiser, you’re going to need to understand the lingo while you’re out on the water. Here’s a glossary of basic nautical terms to have you sounding like a sailor.
Contents
A
Abaft
Toward the stern of the vessel.
Aback
A sail position with the wind striking on its leeward side.
Aft
Around or near the stern of the vessel.
Abeam
At a right-angle to the boat’s center-line.
A-hull
Lashing the helm to the leeward side to ride out bad weather without the sails set.
Amidships
The center of the deck of the vessel between the fore-and-aft.
AIS
Automatic Identification System.
Apparent Wind
The speed and direction of the wind combined with the boat’s movement and the true wind speed and direction.
Astern
To look behind the boat while driving in reverse.
ARPA
Automatic Radar Plotting Aid.
Athwartships
At a right-angle to the aft-and-fore line of the vessel.
Azimuth
The act of measuring the angular distance on the horizon circle in a clockwise method, typically between a heavenly body and an observer.
B
Back
When the wind starts to shift in an anti-clockwise direction.
Back a sail
Sheeting the sail to the windward direction, so the wind fills the sail on the leeward side.
Backstay
The stay supports the aft from the mast, preventing its forward movement.
Baggywrinkle
The teased-out plaited rope wound around the stays or shrouds preventing chaffing.
Ballasts
Iron or lead weights are fixed in a low-access area of the vessel or on the keel to stabilize the boat.
Batten
A flexible and lightweight strip feeds into the sail leech’s batten pocket, supporting the roach.
Ballast Keel
A ballast bolted to the keel, increasing the vessel’s stability to prevent capsizing.
Beam
The widest point of the vessel or a traverse member supporting the deck. On the beam, objects are at a right-angle to the center-line.
Bear Away
Taking the action of steering the vessel away from the wind.
Beat
To tag a zig-zagging approach into the wind or close-hauling with alternate tacks.
Bearing
The object’s direction from the observer measured in magnetic or true degrees.
Belay
To fasten the rope around the cleat using a figure-8 knot.
Bend
Securing the sail to the spar before hoisting it or connecting two ropes using a knot.
Berth
A sleeping quarters on a boat or a slip occupied by a vessel in a marina or harbor.
Bight
The loop or bend in a knot.
Bilge
The round, lower part of the hull where the water collects.
Block
The pulley fixed inside a plastic or wooden casing with a rope running around a sheave and changing to pulling direction.
Boot-Topping
The narrow-colored stripe is painted between the topside enamel and bottom paint.
Broach
The heeling action of the boat when it slews to the broadside while running downwind. Abroach usually occurs in heavy seas.
Broad Reach
The point of sailing the vessel between a run and the beam reach with the wind blowing over the quarter.
Bulkhead
The partitioning wall in the vessel athwartship.
C
Cable
A measurement of distance equal to 0.1-sea mile, 185-meters, or 200-yards.
Center-Line
The center of the vessel along the aft-to-fore line.
Center-Board
A board lowers through a slot on the keel for reducing leeway.
Claw Ring
The fitting slipping over the boom like a claw. It attaches to the main sheet after you finish reefing the sail.
Chart Datum
The reference level on the charts below which the low tide level. The sounding features below the chart datum. The datum level varies depending on country and area.
Cleat
The metal, wooden, or plastic fitting used to secure ropes.
Close-Hauled
The skill of sailing close to the wind, also known as beating.
Clew
The lower, aft corner of the sail where the leech and foot meet.
Close Reach
The point where you’re sailing between the beam reach and the close-hauled or when the wind blows toward the forward of the beam.
Course
The direction that you steer the vessel in degrees. Mariners can use true or magnetic readings or use a compass to plot the course.
Close-Winded
The act of sailing a boat close to the wind.
Cringle
The rope loop at either end of the line reef points or an eye in a sail.
D
Deviation
The difference between the direction indicated by the magnetic meridian and the compass needle, caused by carrying metal objects aboard the vessel.
Dead run
Sailing with the wind blowing to the aft, in line with the center-line of the vessel.
Displacement
The displacement hull design displaces boat weight in the water and is only supported by its buoyancy.
Displacement
The weight of the water displaced by the vessel is equal to the vessel’s weight.
Downhaul
The rope used to pull down the spar or sail.
Drift
To float the vessel with the wind or current. Or the distance covered by the boat while drifting in the current, measured in time.
Draft
The distance between the lowest point on the keel and the center-line of the vessel measured as a vertical distance.
Drogue
The sea anchor thrown over the stern of a life raft or boat or to reduce drift.
DSC
Digital Selective Calling (a function on Marine radios).
Drop Keel
A retractable keel drawn into the vessel’s hull.
E
EPIRB
Emergency Position Indication Radio Beacon.
EP
Estimated Position.
ETD
Estimated Time of Departure.
ETA
Estimated Time of Arrival.
F
Fairlead
The fitting adjusting the feeding line allows you to change the direction of the lead line.
Fiddle
The raised border on cabin tables, chart tables, preventing objects from falling off the surface.
Fathom
Measurement of water depth and rope lengths.
- 1 Fathom = 6-feet = 1.83-meters.
Fix
The vessel positioning plotted by two or more positioning lines.
Freeboard
The vertical distance between the top of the deck and the waterline.
Forestay
The closest stay running between the masthead and stemhead, hankering the mainsail.
G
Genoa
A large-size headsail is available in various sizes, overlapping the mainsail before hoisting in fresh to light winds on all sailing points.
Gimbals
Two concentric rings pivot at right-angles to keep objects horizontal despite the swaying motion of the boat.
GNSS
Global Navigation Satellite System.
GMDSS
Global Maritime Distress and Safety System.
Go About
To change tack by turning the boat into the eye of the wind.
Goosewing
Booming out the headsail in a windward position using the whisker pole to hold it on the opposite side of the mainsail.
Gooseneck
The fitting anchoring the mast to the boom, allowing free movement in all directions.
Guard Rail
This metal rail surrounds the boat’s edges, allowing easy gripping to prevent falling overboard.
Gybe
Turning the stern through the wind to change from one tack to another.
Guy
The spinnaker guy controls the steadying rope for the spar through the aft-fore position of the spinnaker pole. The foreguy keeps the spinnaker pole in the forward position.
GPS
Global Positioning System.
H
Halyard
The rope hoisting the lower sails.
HAT
Highest Astronomical Tide.
Hank
The fitting for attaching the sail’s luff to a stay.
Hatch
The deck opening provides the crew with access to the berth or cabin interior.
Headfoil
The streamlined surround of a forestay featuring the groove allows for the sliding attachment of the luff sides of the headsail.
Head-to-Wind
When the bow of the vessel points into the direction of the wind.
Headway
The forward motion of the vessel through the water.
Heads
The toilet.
Heave-to
The action of backing the jib and lashing the tiller to the leeward side in rough weather conditions. The heave-to encourages the vessel to reduce headway and lie quietly.
Heel
When the vessel exaggeratedly leans to one side.
I
IMO
International Maritime Organization.
IRPCS
International Regulations for Preventing Collisions at Sea.
ITU
International Telecommunication Union
Isobars
The lines on weather maps joining places with equal atmospheric pressure.
J
Jury
The temporary device for replacing damaged or lost gear.
Jackstay
The line running from aft-to-fore on both sides of the vessel. The jackstays allow for the clipping attachment of safety harnesses to prevent being lost at sea when falling overboard.
K
Kedge
A secondary, smaller, lightweight anchor.
Ketch
A dual-masted sailboat featuring a mizzen mast that’s slightly smaller than its mainmast, with a stepped forward position of the rudder post/stock.
Keel
The center-line of the vessel features the attachment of the ballast keel, allowing for the lowering of the center-board.
Kicking Strap
The line for pulling down the boom or keeping it in the horizontal position when on a run or reach.
L
Lanyard
A short length of line attached to an important object that you don’t want to lose, such as the jet ski key. The lanyard can connect to your wrist or lifejacket.
Leech
The aft edge of the triangular sail. Both side-edges of a square sail.
LAT
Lowest Astronomical Tide.
Lee Shore
The shore on which the wind is blowing.
Lee Helm
The natural tendency of vessels to bear away from the direction of the wind.
Leeward
Moving in a direction away from the wind. The direction in which the wind is blowing.
List
The vessel’s leaning to one side due to improper distribution of weight in the boat’s hull.
Luff
The leading edge of the sail. Luffing up is turning the head of the boat into the wind.
Leeway
The sideways motion off course resulting from the wind blowing on one side of the hull and sails.
Log
The instrument for measuring the distance and speed of a boat traveling through the water. It is also the act of recording the details of a voyage in a logbook.
M
Marinized engine
A car engine or motorbike motor adapted for use in watercraft.
MCA
Maritime and Coastguard Agency.
Mast Step
The keel socket locating the base of the mast.
Measured Mile
The distance marked on charts measures one nautical mile between islands at sea or onshore ranges.
Mizzen
The short after-mast on the yawl or ketch.
Meridian
This imaginary longitudinal line circling the earth, passing through both poles, cutting at right-angles through the equator.
MLWN
Mean Low Water Neaps.
MHWN
Mean High Water Neaps.
Mean High Water Springs.
MLWS
Mean Low Water Springs.
MMSI
Maritime Mobile Service Identity.
O
Outhaul
The rope used for pulling out the sail’s foot.
Overall Length (LOA)
The extreme length of the vessel. The measurement from the aftmost point of the stern to the foremost points of the bow. This measurement excludes the self-steering gear, bowsprit, etc.
P
Pan Pan
An emergency call requesting immediate assistance.
Painter
The bowline on a tender or dinghy for towing or making fast.
Pay Out
To gradually let out the rope.
Port
The left-hand side of the vessel when looking forward.
Point of Sailing
The angles of the wind allowing for the sailing of the boat. Or the boat’s course relative to its direction and the direction of the wind.
Port Tack
Your vessel is on its port track when the wind is striking the boat’s port side first, and the mainsail is out to the starboard side.
Line of Position/Position Line
The line on charts shows the bearing of the vessel and the position where the boat mist lie. Or two positional lines providing a location fix.
Pulpit
The steel guard rail fitted to the bow to provide additional safety for the crew when working around the boat’s edge.
Pushpit
The steel guard rail fitted around the stern of the boat to prevent the crew from falling overboard.
Q
Quarter
The section of the vessel midway between the beam and the stern.
R
Range
The difference in water levels between the high and low tides is the range of tides. Or the distance at which you can see the light.
Reef
The act of reducing the sail surface area through folding or rolling additional materials onto the forestay or boom.
Reefing Pennant
The sturdy line allowing you to pull down the leech cringle or luff to the boom while reefing.
Reach
When sailing with the wind blowing onto the beam, with all sailing points between close-hauled and running.
Riding Sail
The small sail you hoist to maintain the steerage way during stormy weather.
Rhumb Line
The imaginary line cuts through all meridians at the same angle. Or the course of the vessel moving in a fixed direction.
Rigging Screw
The deck fitting allowing for tensioning of the standing rigging.
Run
The act of sailing with the wind to the aft of the vessel and with the sails eased into the wide-out, full position.
Roach
The curve in a leech sail extending beyond the direct line formed from clew to head.
Running Rigging
All moving lines like halyards and sheets used for trimming and setting sails.
S
SAR
Search and Rescue.
Schooner
A vessel with two or more masts and the mainmast featured in the aftermost position.
SART
Search and Rescue Transponder.
Scuppers
The toe-rail holes allowing water to drain off the deck.
Sea Room
The room in which the vessel can maneuver clear of submerged dangers.
Seaco*ck
The shut-off valve for the underwater outlet or inlet passing through the vessel’s hull.
Seelonce
This is French for “radio silence.” You’ll use it when reporting a distress call or incident at sea.
Set
The act of hoisting a sail. Or how the sails fit or the direction of a tidal stream or current.
Security
A procedure word for identifying safety calls.
Shackle
A steel link featuring a removable bolt crossing the open end. The shackle comes in various designs, from “S” to “U” shapes and more.
Shrouds
The cables or ropes typically fund in pairs, leading from the mast to the chainplates at the deck level. These shrouds prevent the mast from falling to the side, and it’s part of your standing rigging.
Sheet
The rope attaching to the boom to the sail’s clew allows for the trimming and control over the sail.
Skin Fitting
A through-hull fitting featuring a hole in its skin allows for air and water passing. The seaco*ck is the accessory used for sealing the cavity when not in use.
Sloop
A boat with a single-masted design for one headsail and one mainsail.
Spar
The general term for any metal or wooden pole on board a boat. The pole gives shape to the sails.
SOLAS
Safety of Life at Sea.
SOG
Speed Over the Ground
Spinnaker
A lightweight, large balloon-shaped sail for running or reacting.
Spreaders
The horizontal struts attach to the mast and extend to the shrouds to assist with supporting the mast.
Splice
The act of joining wires or ropes using a weaving process interlacing the fibers in the cable or rope.
Stall
The sail will stall if the airflow over the sail surface breaks up, causing the vessel to lose its momentum.
Standing Part
The part of the line you don’t use when making a knot. Or the part of a rope you use to tie around the knot.
Stanchion
The metal post bolted to the deck in an upright position to support the guard railing.
Standing Rigging
The stays and shrouds provide permanent support to the mast.
Starboard Tack
The vessel is on the starboard tack when the boom is out to post, and the wind strikes the boat’s starboard side.
Starboard
The right-hand side of the vessel when looking forward.
Stay
The rope or wire supports the mast in the fore-and-aft direction. It is a part of the standing rigging for your boat.
Sternway
The sternward movement of the vessel towards the backward direction.
Steerage Way
The vessel has steerage when it reaches sufficient speed, allowing for steering or answering the helm.
Strop
The loop of rope or wire attaches the spar to the block to make a sling.
T
Taffrail
The railing around the vessel’s stern prevents the crew from falling overboard. Modern yachts do not have the elegant wooden railing of older models. Instead, they feature tubular steel or aluminum railings, called Pushpits.
Telegraph Buoy
The buoy marks the position of a submerged cable.
Tail
To pull on the end of the rope or cable, wound around a winch.
Tell-Tale
The compass mounted over the captain’s berth, allowing for the easy reference to what’s going on in the vessel’s helm.
Terminals
The metal fitting forming eyes at the end of cables, wires, or ropes.
Tender
A description for any small boat, usually inflatable models. These boats will take supplies and people between a larger vessel and the shore.
Thermal Wind
The wind occurring from the difference in the heating of the sea and the land by the sun. The sun heats the land faster than the sea, resulting in the onshore wind from the sea replacing the air rising over the land, causing the “sea breeze” phenomenon.
Thumb Cleat
A small cleat featuring a single horn.
Thole Pins
The wooden pegs featuring vertical pairs in the gunwale for constraining the oars for rowing.
Topping Lift
The rope linking the mast to the boom end. It supports the boom, allowing for its lowering and raising.
Track
The progress on the vessel’s journey over the ocean. The trajectory line of the boat.
Topsides
The sides of the hull between the waterline and the deck.
Trampoline
The netting stretching across the hulls of a catamaran.
Trick
A watch period or watch duty at the helm of the vessel.
Transom
Traverse beams forming part of the stern and fixed to the sternpost of a wooden ship.
Tricolor Lamp
A lamp displaying red in proper port sectors, green in the starboard sectors, and white astern. Some authorities permit the tri-color light on smaller boats instead of conventional stern and bow lights.
Turk’s Head
A decorative knot featuring variable numbers of interwoven strands that form a closed loop.
True Wind
The direction and velocity of wind measured by stationary observers. Apparent wind is wind experienced by moving objects.
Tang
Sturdy steel fittings used for attaching standing rigging to the spar or mast.
Tack
The low, forward corner of the sail. Or the action of turning the boat through the wind to get it to blow on the other side of the sails.
Tacking
Sailing close-hauled to work windward on an alternate course. The wind is on one side then the other.
Toe Rail
The low strip of steel, wood, or strapping running along the edge of the deck. You’ll use it in combination with the hand railing to hold your feet to the deck to prevent falling overboard.
Tide
The rise and fall of the ocean are caused by the moon’s gravitational effect on the earth and the ocean.
Topping Lift
The line moving from the mast had to the spar or the boom used in raising it.
Trim
To adjust the sail angle using sheets to achieve optimal efficiency from the sail. Or it describes the action of adjusting the load, influencing the fore-and-aft angle at which it floats.
Track
The course of the boat making good on its travel plan. A fitting of on the boom or mast to the slide on the sail fit. The fitting along which the traveler runs for altering the sheet tension.
True Wind
The speed and direction of the wind when anchored, stationary on the water, or land.
Turn Buckle
The apparatus used for tightening the standing rigging on the vessel.
U
Up Haul
A line used in raising something like a spinnaker pole vertically.
Underway
The vessel is underway when it releases it fastening to shore when it is not aground or at anchor.
V
Vang
See kicking strap.
Veer
The wind will veer when shifting in a clockwise direction. Veering can also mean paying out anchor rope or cable in a controlled manner.
VMG
Velocity Made Good
VHF
Very High Frequency
W
Wake
The disturbed water left behind (astern) the boat as it moves forward in the water, usually caused by a motor.
Weather Helm
The tendency of the vessel to turn into the wind.
Wavelength
The distance between the radio waves.
Weather Side
The side of the vessel to which the wind is blowing.
WGS84
World Geodetic Survey of 1984 (most common chart datum).
Winch
A mechanical device featuring a cable or line attached to a motor. The winch pulls the boat aboard the trailer and helps with the vessel’s launch from the trailer. The winch also gives more pulling power to withdrawing nets or other apparatus from the water.
Whisker Pole
A lightweight pole used for holding the clew out of the headsail when on a run.
Windlass
The winch features a vertical handle and a horizontal shaft used in hauling up the anchor chain.
Windage
The parts of the vessel that increase the drag on the boat. Examples would be the spars, rigging, etc.
Windward
The direction from which the wind blows toward the wind (the opposite way to leeward).
X
XTE
Cross Track Error. The perpendicular distance between two waypoints off track.
Y
Yawl
A dual-masted vessel with its mizzen stepped aft of its rudder post/stock.
