150+ Nautical Terms: Illustrated Guide

Sailing and nautical terms have been refined over centuries, forming a unique glossary that can leave even the most seasoned wordsmiths scratching their heads.

Today, we’ll look at the terminology of words and names used at sea to help you through even the saltiest conversations.

Terms for the components a sailboat consists of

Let’s start with terms for the parts a sailboat is put together from. These refer to each component and explain what they are.

The main parts

Mast: The mast is the big, tall spar that holds up the sails! Some boats have more than one mast.

Mainsail:  The mainsail is the sail behind the mast and on top of the boom. Often just referred to as “the main.”

Boom: The spar that sticks out behind the mast.

Rudder: The rudder is also a fin sticking down under the boat but is located back towards the stern and connected to the wheel or tiller, enabling you to steer the vessel.

Headsail: The sail(s) in front of the mast. Many boats have more than one headsail and can be of different sizes and shapes.

Spreader: The fins or wings that space the shrouds out from the mast.

Hull: This is the body or structure of the boat. Monohulls have one hull, catamarans have two hulls, and trimarans have three hulls – you get the point.

Keel: This is the heavy fin sticking down under the middle of the boat, allowing it to sail. There are many different keel designs, but they are all heavy, and their job is to keep the vessel stable and track through the water under sail.

Helm: This is the position where you steer the boat. Usually, this is a wheel, but it can also be a tiller on many vessels.

Cockpit: The cockpit is the boat’s steering position and where you will find the helm.

Transom: The flat surface across the stern of the boat.

Bow and Stern: The bow is the front part of a boat, while the stern is the rear end. 

Midship: By some called amidships – The center of the boat.

Beam: The widest part of the boat. It is also referred to as the sides on the middle of the vessel.

Waterline: This is the part where the hull (body) of the boat meets the water. Many ships have a painted stripe to mark the waterline, indicating the boat’s load. If you have too much stuff on board, the waterline goes underwater, and it is time to do some housekeeping!

Freeboard: The vertical part of the ship side between the water and the deck.

Deck: The deck is the “floor” of the boat when you are outside. You have probably heard the term “All hands on deck!”

Spar: The general term for a pole made of a solid material like wood or metal used to support a boat’s sail. The mast, boom, spreaders, etc., are defined as spars.

Gooseneck: This fitting connects the boom to the mast and allows it to move horizontally and vertically.

You can read more about the different parts of a sailboat in this article.

The standing rigging which holds the sails

Forestay: The forestay is a wire that runs from the bow to the top of the mast. Some boats, like the Cutter rig, can have several additional inner forestays in different configurations.

Furling system: Most sailboats have their headsail on a furling system, a tube running along the forestay from the bottom furler drum to the masthead swivel. 

Backstay/Aft stay: The wire that runs from the aft of the boat up to the top of the mast.

Shrouds: On most common cruising boats, there are usually four shrouds on each side to support the mast from sideways motion. The shrouds are generally made of wire but can also be rods or Dyneema lines. The cap shrouds run from the masthead through the tips of the spreaders down to the deck. The intermediate shrouds run from the lower part of the mast, through the lower spreaders, and to the deck. The lower shrouds run from the mast under the lower spreaders down to the deck – one forward and one aft on both sides. This is called continuous rigging.

Spreader: The fins or wings that space the shrouds out from the mast.

Turnbuckle: The fitting that connects the shrouds to the chainplate on the deck. These are adjustable, allowing tensioning of the rig.

Chainplate: A fixed strong point bolted on the deck. Usually reinforced with a backing plate underneath. 

You can read more about the standing rigging in this article.

The running rigging which operates the sails

Line: The running rigging on a sailboat often consists of lines, a type of rope with a smooth surface that works well when used on a winch. 

Halyard: This is the line you use to hoist and lower the sail. 

Sheets: The sheet is the line you use to control a sail. The mainsheet controls the angle of the mainsail and is attached between the boom and the mainsheet traveler. The two headsail sheets are connected to the sail’s clew (lower aft corner) and run back to each side of the cockpit.

Outhaul: The outhaul is attached to the clew of the mainsail and used to adjust the foot tension. 

Topping lift: A line attached to the boom’s end runs through the masthead and down to the deck or cockpit. Used to lift and hold the boom and also function as a spare main halyard.

Downhaul: A line used to lower with. Typically used to lower the mainsail when reefing and lowering the spinnaker and whisker poles.

Reef line: Depending on your setup, these lines are used to reduce the sail area of the mainsail.

Shaking a reef: When we sail with a reefed sail and want to increase the sail area back to full, we call it shaking the reef.

Equipment used to operate the running rigging

Block: A pulley with a sheave wheel. These are used to change the direction of a pull on a line or rope and give a mechanical advantage. 

Mainsheet Traveler: The traveler is a horizontal track attached to the mainsheet through a series of blocks. The traveler enables you to adjust the boom from side to side or lock it at an angle.

Cars: The cars are pulleys or blocks attached to a track on the side decks that your headsail sheets run through. They are used to control the angle of the sheet between the clew and the deck. 

Jammer: The jammer is used to lock a line in place. Most sailboats use these for locking the halyards, mainsheet, outhaul, reef lines, traveler lines, boom vang lines, etc. 

Spinnaker Pole: A spar used to wing out a headsail when sailing off the wind, particularly the Spinnaker. 

Whisker Pole: Similar to the spinnaker pole, but typically built lighter and attached to a track on the mast. These can be found in fixed lengths or adjustable lengths. 

Boom Vang/Rod Kicker: A compression pole is used to tension the boom downwards. 

You can read more about the running rigging in this article.

Deck gear and hardware

In-mast furling: A furling system that furls the mainsail in and out of the mast as opposed to the traditional way where the mainsail is secured to the boom and is hoisted and lowered on a track behind the mast.

In-boom furling: A furling system that furls the mainsail in and out of the boom. 

Stack Pack: Also called Lazy Bag or Lazy Pack. A bag with a zip attached to the boom where the mainsail is stored when unused.

Lazy Jacks: A set of lines running from the stack pack to the mast guides the mainsail up and down from the Stack Pack and prevents it from falling on the deck. 

Masthead: Not to be confused with the term masthead rigging. Out of context, the masthead is the top of the mast.

Winch: A metal drum that gives you a mechanical advantage when tightening lines.

Sprayhood: The windshield of the boat that protects the people in the cockpit from sea spray. Some ships have canvas spray hoods that can be folded down or removed. Others have solid sprayhoods, often called a hard dodger or a doghouse.

Bimini: The cockpit’s roof protects you from the elements and provides shelter from spray, rain, and burning sun rays! A bimini can be made of canvas or hard material. The hard bimini is usually called a hardtop.

Outboard: Short-term for an outboard engine, which usually belongs to the dinghy.

Cruisers: What we sailors often call ourselves. Especially those of us living onboard. Although salty, we are definitely handy to have on board as we are also electricians, mechanics, plumbers, and you name it.

Fenders: Like Captain Ron said in the movie, the rubber bumper things you hang off the side of your boat to prevent it from scratching against something like the key side or another boat. Conveniently also used to sit on or as a backrest while relaxing on the deck.

Boat Hook: A long stick with a hook at the end. Used to grab lines, items, and stuff that is too far to reach by hand, like cushions flying overboard. It is also convenient as a tool to push the boat away from another ship or the key. Or to push mud or clay off the anchor. Or catch a wild flying halyard. Most vessels have them on board, and you want one or two. (They tend to get lost at sea).

Guard Rail: This can be a flexible wire or a solid metal rail surrounding the boat to prevent us from falling overboard. Some also use a net as an addition for increased safety.

Pushpit: The metal guard rail around the stern of the boat. This is where the guard rail is secured on the stern. A common place to mount the BBQ, life raft, and the outboard for the dinghy. 

Pulpit: The metal guardrail on the bow. This is where the guard rail is secured onto the bow.

Stanchion: The metal bar that keeps the guard rail in place around the boat between the pushpit and the pulpit.

Arch: A big structure usually made of stainless steel on the back of a boat. Often used to mount a variety of items like antennas, radars, solar panels, wind generators, etc.

Ground Tackle: This consists of your anchor, your anchor chain, the link between the two, and the connection between the chain and your boat. The ground tackle is basically the system that holds your boat to the ground.

Windlass: The winch that hoists or lowers the anchor and chain. Most boats have one on the bow, and some have one on the stern, too. These incredible things can be electrical or manual (some are both) and are essential to anchor your boat when not in a port or marina. Try to haul the anchor manually once – you’ll put a windlass on the top of your wish list pretty quickly…

VHF Radio: Very High-Frequency Radio that broadcasts on the VHF network and makes you able to communicate with others around you. Sadly, you won’t be able to tune in to your favorite radio show on these. Still, they are invaluable at sea for communication.

Chart Plotter: A navigation computer that shows various information on a screen, like charts, routes, radar images, etc.

Parts below the decks

Companionway: The “front door” of the boat. This is where the steps lead from the cockpit or deck down below. It is usually opened and closed using a hatch, two doors, or a plate.

Galley: The kitchen of a boat is never to be called a kitchen. Always use the term galley when you are onboard!

Saloon: This is the boat’s living room and usually where you find the settee and dinette.

Settee: The couch in a ship.

Dinette: This is the area where you can sit down at a table and eat your dinner. It’s also perfect for consuming rum in good company and a game of cards.

Cabin: These are the “rooms” onboard but might not necessarily be the “bedrooms.”

Head: There are no bathrooms on a boat, only heads. If your skipper tells you to go and clean the head, getting out the shampoo won’t do you any good.

Nav station: Usually a chart table and a console with mysterious instruments like radios, chart plotters, radar screens, and all sorts of complicated electronics. This is often where adventures are planned and the skipper’s favorite seat onboard. (At least, that is my favorite and where all this content is created!).

Bilge: The space in the bottom of the hull where water collects and sometimes a storage space for all sorts of things. It usually contains a bilge pump to pump out water that finds its way into the boat in various places. You may have heard the phrase: “Treasures of the bilge.” Now you get it!

Berth: A place in the boat where you can sleep. This doesn’t necessarily have to be a bed and can often include the sleeping space in the salon. The term sea-berth usually refers to a sleeping position where you are tucked well in and can sleep when the boat is heeling over and moving around.

V-berth: The bed in the front cabin is shaped like a V.

Bulkhead: A wall inside the boat, usually supporting the structure.

Terms used for directions and navigation

Port and Starboard: Port refers to the left side of the boat when facing the bow (front), while starboard signifies the right side. 

Windward and Leeward: The windward side refers to the side of a boat facing the wind, while the leeward side is the side sheltered from the wind. These sailing terms also apply to geographic features, like islands or coastlines, that offer protection from the wind.

Chart: A nautical chart is a map specifically designed for marine navigation, depicting water depths, shoreline features, navigational aids, and potential hazards.

Compass: A compass is an essential navigational instrument that indicates magnetic north, allowing sailors to determine their heading and steer their vessels accordingly.

Course: The course is a vessel’s intended direction of travel, expressed in degrees from true or magnetic north.

Heading: The heading is the actual direction a vessel points, also expressed in degrees from true or magnetic north.

Latitude: Latitude is a geographic coordinate that specifies a location’s distance north or south of the equator, measured in degrees, minutes, and seconds.

Longitude: Longitude is a geographic coordinate that specifies a location’s distance east or west of the Prime Meridian, measured in degrees, minutes, and seconds.

Waypoint: A waypoint is a specific location, defined by its latitude and longitude, that serves as a reference point for navigation.

Bearing:  The angle between the observer’s position and a distant object, measured in degrees from true or magnetic north.

Fix: A fix precisely determines a vessel’s position using various navigational methods, such as bearings, GPS, or visual landmarks.

Dead Reckoning: Dead reckoning is a method of estimating a vessel’s current position based on its previous position, speed, and course over time.

Tide: Tides are the regular rise and fall of sea levels caused by the gravitational forces exerted by the Moon and Sun. 

Current: Current refers to the horizontal movement of water in a particular direction. Currents can significantly affect a vessel’s speed and course, so make sure to consider them when sailing and navigating.

Buoy: A buoy is a floating device anchored in a body of water, such as an ocean, sea, lake, or river, to serve various purposes, including navigation, marking channels, identifying hazards, or indicating mooring locations.

The names of different sails and their parts

Mainsail: The mainsail is the sail behind the mast and on top of the boom. 

Genoa: A Genoa is a headsail that extends past the mast and overlaps the mainsail. 

Jib: A Jib is a headsail that does not overlap the mainsail. 

Staysail: A staysail is usually found on cutter rigs and is the sail set on the inner forestay.

Yankee: A yankee headsail is used similarly to a Genoa or Jib but has a high-cut clew and is often used on cutter-rigged boats together with a staysail.

Mizzen sail: A mizzen sail is typically a small triangular sail set on the aft mast of a boat with several masts, like the ketch rig.

Storm sail: A storm sail is a small, strong sail to be used in heavy weather conditions where the headsail is furled to the point where its shape doesn’t give you drive anymore or/and when you want a smaller mainsail than your reefing setup allows you. The storm sails provide stability in the vessel in heavy weather sailing.

Spinnaker: A Spinnaker is a symmetric light wind sail used to sail off the wind at deep angles between 120 and 180 degrees.

Gennaker: A Gennaker is a cross between the Genoa and Spinnaker. It has the same type of light fabric as the Spinnaker but is asymmetrical like a Genoa with a tack set on the bow and a sheet led back from the clew to the stern of the boat.

Code Zero: A code zero sail is a cross between a Genoa and a Gennaker. It is also designed for light wind with its lightweight fabric but has a different shape than a Gennaker. This makes it able to be used while sailing upwind, unlike the Gennaker.

Parasailor: A parasailor is similar to a spinnaker but with some differences. It has a double-layer wing that inflates as the sail gets filled with air. This wing works like a batten and keeps the leech out while generating lift on the bow, making it effective between 70 degrees and all the way down to 180 degrees dead downwind.

The different parts of a sail

Tack: The tack of the sail is the lower forward corner.

Clew: The clew of a sail is the lower aft corner.

Head: The top corner of a sail. 

Foot: The foot of the sail is logically the bottom part of the sail between the clew and the tack.

Luff: The luff is the front edge of the sail between the tack and head.

Leech: The leech is the aft part of the sail between the clew and head. 

Telltales: Telltales are small ropes, bands, or flags attached to the sail to give you an indication of the airflow around your sail. 

Battens: Battens are slates or tubes inserted in pockets on the mainsail to help it keep its shape better and increase its lifespan.

Learn more about the different types of sails in this guide. 

Terms used when we talk about wind and weather

Gust: A gust is a sudden, brief increase in wind speed, often accompanied by a change in direction.

Squall: A squall is a sudden, strong wind that typically lasts for a short period and is often associated with rapidly changing weather conditions, such as thunderstorms or cold fronts.

Barometer: A barometer is an instrument used to measure atmospheric pressure. Changes in atmospheric pressure can indicate upcoming weather changes.

High-Pressure System: A high-pressure system is an area of relatively high atmospheric pressure, characterized by sinking air and typically associated with calm, clear weather.

Low-Pressure System: A low-pressure system is an area of relatively low atmospheric pressure, characterized by rising air and typically associated with clouds, precipitation, and potentially stormy conditions. Sailors usually refer to these systems as a “low.”

Front: A front is a boundary separating two air masses of different temperatures and humidity levels. Fronts are associated with changes in weather conditions and can cause sudden wind shifts and varying wind strengths.

True Wind Speed, or TWS: The actual wind speed affecting you at a point when you are standing still.

True Wind Direction, or TWD: The direction the wind is blowing from.

True Wind Angle, or TWA: The angle between your boat’s heading and wind direction.

Apparent Wind Speed, or AWS: The wind affecting the boat while in motion.

Apparent Wind Direction, or AWD: The direction of the wind in relation to your boat underway.

AWA – Apparent Wind Angle: The angle to wind while you are underway

Beaufort Scale: The Beaufort Scale is a system used to measure wind speed, ranging from 0 (calm) to 12 (hurricane). You can learn more about it at MetOffice here.

Saffir Simpson Hurricane Wind Scale: A scale describing hurricane wind speeds in categories from 1 to 5.

Learn more about the difference between actual and apparent wind in this guide.

Terms we use when cruising at speed under sail

Port Tack: When the wind blows on the port side of your sails

Starboard Tack: When the wind blows on the starboard side of your sails

Tacking: When you steer the boat from a starboard tack to a port tack and vice versa upwind.

Gybing: When you steer the vessel from a starboard tack to a port tack and vice versa downwind.

Heeling: When the wind fills the sails and leans the boat over to the side.

NM: Nautical Miles

Kt: Knots – A measurement of speed used on boats.

Deg: Short for degrees

SOG: Speed over Ground, usually measured by GPS

SOW: Speed over Water, usually measured by the boat’s speed log transducer.

COG: Course Over Ground, the direction your boat is moving towards.

HDG: Heading, the direction your boat is pointing towards.

Boom preventer: A line or rope tied to the end of the boom and led forward of the mast to prevent it from swinging over when sailing off the wind.

Overpowered: When wind overpowers the boats’ ability to steer a straight course. This typically happens when you try to sail above your boat’s hull speed, carrying too much sail area in relation to the wind, or your sails are poorly trimmed.

Hull Speed: The speed your boat has achieved when its created wave has the same length as the hull’s water length. Many displacement sailboats (the ones that don’t plane on top of the water) get hard to steer when going faster than this. You can learn more about how to calculate your hull speed in this guide: https://sailingellidah.com/average-distance-sailed-in-a-day/

Pro Tip: Your COG and HDG will sometimes differ due to wind and current pushing you sideways.

Terms for the boats heading in relation to the wind

These sailing terms are best known as our points of sail and describe the vessel’s heading in relation to the wind:

Close Hauled: When sailing close-hauled, the vessel’s heading is as close to the wind as possible, typically between 35-50 degrees.

Close Reach: When sailing at an angle between 50 and 80 degrees, give or take.

Beam Reach: The wind comes in from the side.

Broad Reach: When bearing away from 90 degrees to around 135 degrees.

Running: When sailing downwind.

You can learn more about the 5 points of sails in this guide: 

Final Words

I know there are a lot of nautical words and terms to keep track of, but luckily, no one expects you to know them all right away. You’ve probably already taken note of the most important ones, which means you’ve taken a giant leap in the right direction. Keep at it; you’ll speak like the saltiest seadog before you know it.

Did I forget to mention any terms you know of? Let me know in a comment below!

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