Glossary: essential terms a sailor should know

Glossary: essential terms a sailor should know

Brush up on your nautical vocabulary with these commonly used terms. Which ones do you know?

We have put together a comprehensive list of essential sailing terms to enhance your nautical knowledge. Delving into diverse areas such as meteorology, navigation, and boat equipment, our glossary covers sail types, boat components, and crucial units of measurement and abbreviations that every sailor should be familiar with. Plus, you'll find terms unique to charter boats, the boat rental process, safety at sea, signalling aids, and modern sailboat technology.


Anchor windlass is a mechanical device used to hoist and lower the anchor and its chain on a boat. It operates under high tension and typically has its own circuit breaker to protect it from electrical overloads. When using an anchor windlass, it is essential to allow for short breaks during operation to prevent it overheating and any resultant damage to the equipment.

Anticyclone is an area of high air pressure.

Apparent wind is the wind we perceive when we are on board and results from the vector sum of the real wind and the wind generated by our motion while sailing. The topic of apparent wind is covered in detail in our article — Apparent vs. true wind.

Autopilot is a device designed to steer a boat along a predetermined course. It independently adjusts the rudder as required, ensuring the vessel follows the set path to its destination as accurately as possible. 


Baby net or safety net is a safety feature that prevents small children from falling off the deck into the water. It is a net similar to a fishing net, which is installed along the boat's railings. A baby net does not come as standard with a rental boat, so always discuss it with the salesperson when booking if you want to order the net from the charter company. We discuss safety features in our article — Sailing with kids: how to keep all of you safe and happy.

children's nets

Safety nets on the boat effectively prevent children from falling into the water.

Barber hauler is a sail control device used to adjust the angle of the jib or genoa sail in relation to the wind, mostly found on more sporty boats. It consists of a line or tackle system attached to the clew of the sail, allowing sailors to fine-tune the sail's position for optimal performance and improved windward efficiency.

Bathing or swim platform, is a foldable structure located at the stern of a boat, providing easy access to the water for swimmers or during training activities. When sailing, it is advised to keep the bathing platform closed and secured in place, rather than left extended.

Batten is the reinforcement in the mainsail. Mainsails are generally classified based on their shape and construction, with variations such as full-batten, partial-batten, or no-batten mainsails.

Beaufort scale is a widely recognized scale in the sailing world. It categorizes wind forces and their corresponding effects on sea surface conditions, allowing skippers to estimate wind strength visually. By observing the behaviour of the sea surface and the wind's impact on it, sailors can use the Beaufort scale to make informed decisions about their sailing course and speed.

Bearing compass is a type of compass that is used to determine the bearing, or direction, of an object or location relative to the compass itself. It is commonly used in navigation to determine the direction of a distant landmark or to maintain a specific course while sailing.

Bimini is an alternative term for a sun canopy that provides shade for the helmsman's station and the rear portion of the cockpit. In the rain, it serves as a slight protection from the water. Often, however, sailors fold it up for sailing, and sometimes there is no other way to do it, as the mainsail sheet passes through it.

Boom is a horizontal spar, typically made of aluminum or carbon fiber, that attaches to the mast and holds the foot of the mainsail. It runs perpendicular to the mast and is held in place by a combination of topping lift, mainsheet, and outhaul.

Bora is a powerful, cold wind originating from the north to north-east that frequently affects the Adriatic Sea. It can pose a significant risk to sailors navigating the region. To learn more about the Bora and its impact on sailing in Croatia, check out The Bora: the scourge of the Adriatic.

Bow thruster is a mechanism located at the bow of a vessel that assists with maneuvering while in port. It is not intended to replace the main engine and should not be used while sailing. The primary function of a bow thruster is to help shift the boat's bow to port or starboard. It's essential to operate the bow thruster with caution, as it has a high voltage. Use short, intermittent presses (2-3 seconds) rather than prolonged holds to prevent the bow thruster from burning out and becoming inoperable.

Bowsprit is a spar that extends from the bow of a sailboat. It is used to attach the forestay, which supports the mast, and to extend the sail area forward. On historic ships it is slightly angled upwards towards the sky. On more modern boats it extends straight out from the bow and may be retractable or foldable to make docking and storage easier.

Brackish water is water that is neither salty like the sea nor fresh like freshwater streams. Its salinity is somewhere in between. It is most often found at the mouths of rivers or in lakes by the sea.

Breeze is a periodic wind phenomenon caused by differences in air temperature between day and night. According to the time when it occurs, it is distinguished between day (sea) and night (land). The breeze is a beautiful sailing breeze. Read more about breezes in our guide — Understanding land and sea breezes: how they can affect your sailing.

Buoy field is an arrangement of multiple buoys within a bay, anchored to concrete blocks on the seabed. Typically, a fee is charged by the operator for using these buoys, but the cost is generally lower than docking at a pier or marina.


Cardinal marks are navigational aids that indicate the location of safe water relative to a hazard. They are named after the four cardinal points: North, East, South, and West.

Cardinal marks chart for sailors

Cardinal marks

Charter company owns the boats that are available for rental and acts as a partner to businesses like ours. We feature their boats in our search portal.

Check-in is the process of taking over a charter boat. You can find out more about what you need to look out for in our guides Boat check-in: examining a yacht down to the last screw and Inspecting your rental boat: a complete checklist and guide

Check-out is the handing over of the boat to the charter company at the end of your yacht charter holiday.

Cirrus clouds are characterized by their wispy, hair-like appearance, resembling algae, tufts, or manes. These clouds are translucent, cast no shadow of their own, and have extremely fine fibres.

Cleat is a metal object attached to the deck of a boat used to secure the boat. It may also be on a pier.


Cleats can also be found on the pier.

Cockpit is an area towards the rear of a sailboat, typically designed for the crew to steer, navigate, and control the boat. It is the central location where the helm, rudder, and various lines, winches, and controls for sails are accessible.

Code Zero is a unique sail that isn't found on all sailboats. It is similar to a larger, deeper genoa but made from a lighter material. The sail is equipped with its own furling line and endless loop for easy deployment and storage.

COG (Course Over Ground) refers to the direction of a vessel's movement measured in relation to the earth's surface or the seabed.

COLREG is a shortened term in English that stands for the Convention on the International Regulations for Preventing Collisions at Sea. These regulations provide rules for watercraft operation, ensuring clear right-of-way guidelines.

Cumulus clouds are generally puffy and white, with a flat base and a rounded top. They can have a cauliflower-like appearance, and their edges may be well-defined or fuzzy. 

Cunningham is a type of rope that runs from the base of the mast to the lower edge of the mainsail, allowing the sailor to stretch the edge of the sail downward. It is typically located on the side of the mast that is opposite to the outhaul.

Cyclone is an area of low air pressure.


Dew point is the temperature at which the air becomes saturated with water vapour and begins to condense into dew.

Dinghy, also known as a tender, is a small boat often used by sailors to transport themselves and their supplies to and from their anchored or moored boat. Dinghies can be inflatable or made of hard materials like fiberglass or aluminum.

Dodger, also known as sprayhood, is a protective structure mounted at the front of the cockpit on a sailboat. It shields the cockpit and companionway from wind, spray, and waves, providing shelter and improved comfort for the crew


EPIRB (Emergency Position Indicating Radio Beacon) is an emergency distress beacon that is used to transmit a distress signal to rescue authorities in the event of an emergency situation


Fender is a cushioning device made of rubber, plastic or foam that is used to protect a boat's hull from damage when it is moored against a dock, pier or another vessel. 

Flare is a signalling device used to call for help in an emergency. Its misuse is punishable.

Fog horn is a signalling device that produces loud, low-pitched sound blasts to warn other vessels of the presence of your boat in conditions of reduced visibility, such as fog or heavy rain.

Foil is a hydrodynamic device that is used to lift the hull of a boat out of the water and reduce drag. Foil technology is also used in other water sports such as windsurfing, kiteboarding, and wingfoiling.

foiling catamaran

This is what a foil looks like on a racing catamaran.


Gangway is a temporary bridge or walkway that connects a boat to a dock, allowing people to move between the two structures.

Gennaker is an additional sail that is similar to a genoa. It is made of lighter material, which makes it ideal for lighter winds. Gennakers often have distinctive colours, and there are several reasons why sailors might want to rent and try one out.  Check out our 5 reasons to rent a gennaker.

Genoa, also known as genoa jib, is a type of sail that is positioned forward of the mast and is used on sailing boats. It typically covers the area from the mast to the bow of the boat, and is larger than the mainsail. It can range in size from 100% to 150% of the foretriangle, which is the triangle formed by the mast, forestay, and deck.

GPS, which stands for Global Positioning System, is a satellite-based navigation system that provides location and time information anywhere on Earth. Sailors can use an electronic GPS device to accurately determine their position on the water.

Gulets are double-masted boats designed and built based on traditional Turkish wooden sailing boats. One of the typical destinations for gulets, which we also offer, is Turkey.

Gybe or jibe is a sailing maneuver where the sailboat's stern is turned through the wind to change the wind direction from one side of the boat to the other, usually while sailing downwind. The boom of the sail swings across the boat during a gybe, and it should be performed carefully to prevent accidents and damage to the boat and crew.


Harness is a safety device used in sailing that is attached to a sailor's body or life jacket and secured to the boat's deck with a buckle to prevent falling overboard.

Halyard can is a rope used to raise different types of sails such as the mainsail, jib, genoa, spinnaker, and gennaker. Each sail will typically have its own dedicated halyard to hoist it up the mast.

Hatch is an opening on the deck or cabin top of a boat used for ventilation, access, or as an emergency exit.

Horseshoe life buoy is a U-shaped buoyant device made of foam or other buoyant material, and is used as a safety device in the event of a person falling overboard. It is typically kept on board a boat, often near the stern on the railings.


Impeller is a small component (propeller) in the engine that provides suction and circulation of seawater in the engine cooling. Because it is such a crucial component, you will usually find a spare one on board.

Isobar is a line on a synoptic chart that connects two points where the atmospheric pressure is the same.

Isolated hazard refers to a navigational mark or buoy placed in the sea to indicate a potential danger, such as a shoal, rock, or other underwater obstruction located in open water. While it is possible to sail around an isolated hazard, it is generally recommended to maintain a safe distance by navigating around it in a larger arc.

Isotherm is a line connecting two points of the same temperature.


Jib is the term for a headsail that fills no more than 100% of the area between the forestay and the mast.

Jugo, also known as Sirocco, is a moody and unpredictable south to south-easterly wind found in the Adriatic. Find out more about it in our guide — The Croatian Jugo wind: when and where it occurs and why to be on the lookout!!


Keel, which is the heaviest component located beneath a boat and has the lowest center of gravity, plays a vital role in maintaining the vessel's stability. It typically accounts for up to 40% of the boat's weight and can have a fin or bomb shape. The keel's primary purpose is to stabilize the boat and prevent it from capsizing by helping to restore it to a horizontal position when it is tilted due to wind or waves.

Kicker, also known as a boom vang or vang, is a mechanical device consisting of ropes or a piston that is connected between the deck, boom, and the base of the mast. It is used to control the shape of the mainsail by adjusting the tension on the leech of the sail and controlling the boom's vertical position.

Knot can be the one on the rope or also a unit indicating the speed of the boat. It's equivalent to 1.852 kilometres per hour.


Lazy bag (sometimes called a lazy pack or stack pack) is a large cover designed to store a folded mainsail on the boom.

lazy bag

The lazy bag is attached to the boom and the mainsail falls into it when it is folded.

Lazy jacks are lines holding the lazy bag.

Leech or leach is the back edge of the sail.

Libeccio or Lebić is a south-westerly to westerly wind and is typical of northern Corsica, the coast of France, Italy and also the Adriatic, where it usually arrives just after the Jugo/Sirocco. Read more about this wind in our article — The Libeccio/Lebić: a stubborn, unpredictable wind.

LOA stands for Length Overall, which is the maximum length of a vessel measured from the foremost point of the bow to the aftermost point of the stern, typically along the waterline.

Logbook is a document where a sailor writes down details of a voyage including weather, the boat's course, position and other information.


Mainsail, sometimes also referred to colloquially as the "main," is the sail that is hoisted up the mast of a sailboat.

Mainsheet track or traveller is the rail on which the mainsheet car or block moves back and forth, allowing for adjustment of the angle of the mainsail relative to the wind. Racing boats typically have the mainsheet track located in the cockpit for maximum adjustability, while recreational sailboats may have it located closer to the mast.

Marina is just another name for a harbour for recreational boaters. A marina often has social facilities, a shop, offices of charter companies, etc.

Marinero is a Spanish term for a marina worker who assists with various tasks, such as helping boats to dock and providing assistance to boaters with any issues or needs they may have while in the marina.

Mast is a tall vertical spar that supports the sails on a sailing vessel. It is typically located in the center of the boat and is stepped (or mounted) on the keel or deck. The mainsail is hoisted up the mast and attached to it, while the jib or headsail is usually attached to the forestay, which is a cable or wire that runs from the top of the mast to the bow of the boat. 

Meltemi is a dry northerly wind that occurs mainly in the Aegean and eastern Mediterranean, from late May to late September. Read more about this wind in our guide — The Greek Meltemi: friend or foe?.

Mistral is a cold wind found, for example, in France. It works on a similar principle to the Croatian bura. For more information, check out our article — The Mistral: a turbocharger for experienced sailors.

MOB stands for Man Overboard, which refers to the emergency situation where a crew member has fallen into the water and immediate action is required to retrieve them. Find out more in — Man Over Board (MOB): a step-by-step guide.

Mooring can refer to any type of permanent anchor or buoy to which a boat can be tied upCommonly on the Adriatic, it consists of a concrete block on the bed and a rope leading to shore. The boats are then moored to it at the pier or jetty. It is a very convenient and easy way to moor a boat.

Mooring bollard is a sturdy vertical post or pole, often made of metal or wood, that is used as a mooring point for boats.

Mooring bollard

Bollards serve both recreational boats and transport or cargo ships. Therefore, it is often large in size.

Mooring hook is pole with a hook used by boaters to grab onto a mooring buoy or other floating object in the water and retrieve the mooring rope attached to it.


Nautical flag alphabet (International Code of Signals) is a special set of characters, words and flags that sailors around the world use to communicate.

Nautical alphabet

The nautical alphabet is also used in aviation.

Nautical mile is a unit of distance at sea. 1 NM equals 1.852 m. But be aware that it differs in length to a land mile!


Occluded front is a type of weather front that occurs when a fast-moving cold front overtakes a slower-moving warm front. This results in the warm air being lifted off the ground and creating clouds and precipitation.

Offshore typically refers to sailing or boating in open water, away from the coast or shore. This type of sailing can involve more challenging conditions and requires greater skill and experience. Read more about it our article — Beyond the shoreline: 10 things to consider when offshore sailing.

Outboard engine or outboard motor is a small portable engine designed to power a dinghy. It is ordered as an extra with the boat rental.

Outboard motor and seagull

What the seagull's sitting on is an outboard motor.

Outhaul is a control line on a sailboat that adjusts the tension of the mainsail foot, which is attached to the boom. It allows the sailor to control the depth and shape of the mainsail along the boom.


Plotter is an electronic device used for navigation that displays and tracks the boat's position and movement using GPS technology. It is often located in the cockpit.

Port (side) is the term for the left-hand side of the boat when facing forward.

Porthole is a term for a small, usually circular window on a boat or ship.

Preventer or boom preventer is an auxiliary line or rope that is rigged from the end of the boom to a sturdy point on the deck, mast, or other secure attachment point on the boat. The purpose of the preventer is to restrict the boom's movement and prevent an accidental or unintentional jibe, which can happen when sailing downwind or on broad reach courses.

Propeller is a device consisting of blades that rotate to provide propulsion for a boat's engine. It is often located at the stern (back) of the boat and is powered by the boat's engine.

Propwalk is a phenomenon that occurs when a boat's propeller produces a lateral force that causes the boat's stern to move to one side when the engine is in gear. This is particularly noticeable at slow speeds and when maneuvering in tight spaces, such as a marina or dock.

Propwash is the turbulence created by the rotation of the propeller. Propwash deflecting off an angled rudder allows even large boats to turn in a tighter space.


Quebec flag signal (yellow) in the International Code of Signals means "My vessel is healthy and I request free pratique" which is a signal made by a ship entering port to request permission to enter and clear customs and immigration. It is usually used when sailing abroad. To learn more about crossing borders, take a look at Can you cross national borders with a charter boat?



Reefing is a technique used to reduce the area of the sail in order to maintain control of the boat and prevent it from being overpowered in strong winds. Charter boats usually have 2 or 3 degrees of reefing available.

Railing is another term for the guardrails around a yacht.

Rigging refers to the system of ropes, wires, and hardware that support and control the sails and masts on a boat or ship. It includes not only the mast, boom, and standing rigging (wires or rods that support the mast), but also the running rigging (ropes that control the sails), such as halyards, sheets, and control lines.

Rudder blade is the part of the steering system that is underwater. A boat may have one or two rudder blades.


Safety line is a line running along the deck of the boat by which sailors fasten their harnesses to prevent them from falling into the water when the boat is heeling or in large waves. The safety line is not automatically installed on the boat and must be installed separately.

Self-tacking jib is a type of headsail that is specifically designed to tack without the need for adjusting the sail position or manually pulling on the sheets. The sail is attached to a track or a traveler that runs athwartships on the boat and allows the sail to pivot and change sides without having to be moved or adjusted manually.

Shackle is a small metal device used to attach a line to a sail. It is used to connect the sail to the halyard or other lines on the boat. It can also be used to connect different sails together or to connect a sail to a spar or other structural element of the boat.

Sheet is a rope or line used to control the angle and shape of a sail. There are different sheets for different sails, such as the mainsheet for the mainsail, the jib sheet for the jib sail, and the spinnaker sheet for the spinnaker sail.

Shrouds are actually a type of standing rigging, which are the fixed lines or wires that support the mast of a sailboat. They run from the mast to the sides of the boat, and help to keep the mast upright and stable.

Spreader is a horizontal strut that extends from the mast to the side of a sailboat, providing support for the mast and helping to spread the shrouds that support the mast.

Spinnaker pole is a long and sturdy pole used to hold the clew (bottom corner) of a spinnaker sail out from the mast of a sailing boat.

Steering wheel is the device used to control a boat's direction. It is connected to the rudder blade through a steering mechanism. Boats can have one or two steering wheels depending on size and design.

Storm sails are special sails, usually orange in colour, whose small surface area and strong material allow sailing in storms. The sails are not installed on the boat all the time, they need to be unpacked from the hold when needed. Ask at check-in where the storm sails are located on the boat.

storm sails

Storm sails often have a distinctive colour.

Skipper is just another name for the captain, the skipper of a yacht. Would you like to become a skipper too? Take a look at our sailing courses.

Spinnaker is a large, lightweight and often colourful sail that is designed to be used when sailing off the wind, such as on a reach or a downwind leg.The spinnaker is attached to the boat's mast and is supported by a spinnaker pole.

Spin-out refers to a situation in which a boat, while sailing downwind, loses control and starts turning towards the wind.

Sprayhood is a protective covering, typically made of canvas or other durable material, that is installed over the companionway (entrance to the cabin) of a sailboat. Its primary purpose is to shield the cockpit and the interior of the boat from wind, spray, and rain while underway

SRC stands for Short Range Certificate, which is a certification required for operating a marine VHF radio.

Starboard is the term used to describe the right-hand side of a boat when facing forward.

Stay is a term used to refer to a piece of rigging that helps support the mast of a sailing vessel. It typically runs from the top of the mast to the bow of the boat, forming a triangle shape along with the mast and the boat's deck.

Stratus is a type of low-level cloud characterized by its uniform, featureless appearance that often covers the entire sky.

Synoptic map, also known as a weather map, is a graphical representation of current weather conditions created using data collected from weather stations, satellites, and other sources.


Tack is the maneuver of turning the sailboat against the wind.

Telltales are pieces of yarn or fabric that are attached to a sail, stay, or rigging on a sailboat. They are used as a guide for trimming or adjusting a sail by providing information about the airflow around the sail. 

Telltales on a sail

Telltales on a sail

Tender is another word for dinghy.

Tiller is a rod used to move the rudder blade and control the direction of the boat. It is often used on smaller sailboats instead of a steering wheel. In case of an emergency, there might be a spare tiller onboard as a backup.

Topping lift or topenant is a line that runs from the end of the boom to a point high on the mast, which supports the boom and prevents it from dropping too low when the mainsail is not raised.

Trade wind is a wind that blows steadily towards the equator from the northeast in the Northern Hemisphere and from the southeast in the Southern Hemisphere, usually found in tropical regions.

Transom is the reinforced vertical portion located at the stern of a boat. It connects the sides of the boat, giving it form and structure. The transom is also where an outboard motor is typically attached to the vessel and where the boat's name may be painted.

True wind is the actual wind that exists in the environment and is not affected by the motion of the body or the vessel. It is the wind that would be felt if the vessel were stationary.  Find out more in our article — Apparent vs. True Wind.


We found nothing for this letter except in the nautical alphabet (U: Uniform – you are heading into danger). If you can think of something to go here, get in touch.


Venturi wind is a localised wind flow originating and blowing out of a strait, for example between hills or rocks.

VHF (short for Very High Frequency) is electromagnetic waves that allow radio communication between ships, aircraft, ports, etc. 


Winch is a mechanical device consisting of a drum that rotates either manually or powered by an electric or hydraulic motor. The rope or line is wrapped around the drum and as it rotates.


Drum-shaped rope winch.

Wind vane (otherwise known as a weather vane, wind indicator or a wind sock) is a small device at the end of the mast whose arrow indicates where the wind is blowing from.

X, Y, Z

If you can think of a term that could be here, please write to us.

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