Glossary

A navigational method used to estimate a vessel's current position based on a previously known position, factoring in speed, time, and course...

The vertical distance between the waterline and the lowest point of the hull, typically the keel, indicating how deep the vessel sits in the...

To be carried along by currents or wind without a set course or direction. The movement of a vessel or object caused by wind, currents, or tides,...

A device, often resembling a small parachute or cone, deployed from a vessel or lifeboat to create drag and stabilise its movement in rough...

The vertical distance between the seabed or a drying feature, such as a rock or sandbank, and chart datum, which is usually lowest astronomical...

An automated VHF and MF/HF radio communication system used in maritime environments to send distress alerts, establish contact, and exchange...

The measured distance, typically in nautical miles, between a vessel's current position and a predetermined navigational point or...

A high-performance synthetic fibre known for its exceptional strength-to-weight ratio.

It is often used in marine applications for rigging,...

The period during which the tide is receding, causing water levels to fall as it flows away from the shore towards the sea.

Ebb tide is a...

An Electronic Chart Display and Information System (ECDIS) is a geographic information system used for nautical navigation that complies with IMO...

Pronounced: ECK-oh

The term for the letter E in the NATO Phonetic Alphabet.

A European intergovernmental organisation that provides medium-range weather forecasts for its member countries and the wider international...

The International Maritime Signal Flag Echo.

Meaning

I am altering course to starboard.

A specially designed mooring system that allows vessels to anchor without damaging the seabed, particularly sensitive habitats like seagrass beds...

An Electronic Chart Display and Information System (ECDIS) is a geographic information system used for nautical navigation that complies with IMO...

A digital database of maritime chart information designed for use with Electronic Chart Display and Information Systems (ECDIS) to support safe...

This shape represents the Letter E (Flag Semaphore) and the Number 5 (Flag Semaphore).

International Morse Code sequence representing the letter E.

A safety device used in maritime emergencies to transmit a distress signal and location to search and rescue authorities via satellite...

A digital database of maritime chart information designed for use with Electronic Chart Display and Information Systems (ECDIS) to support safe...

A flag that denotes the nationality of a vessel, typically flown at the stern of a ship or boat.

An ensign is a crucial part of maritime...

The approximate location of a vessel determined by dead reckoning, and accounting for external factors such as wind (Leeway) and Tide.

An...

A safety device used in maritime emergencies to transmit a distress signal and location to search and rescue authorities via satellite...

Waving both flags up and down indicates an error in the communication.

Repeated eight times, Letter E (Flag Signal) indicates an error.

The approximate location of a vessel determined by dead reckoning, and accounting for external factors such as wind (Leeway) and Tide.

An...

The predicted time at which a vessel is expected to reach a specific destination, based on current speed, course, and environmental...

The predicted time at which a vessel is expected to reach a specific destination, based on current speed, course, and environmental...

Strong, dry north to north-easterly katabatic winds that blow seasonally over the Aegean Sea during the summer months.

The Etesians, also...

A European intergovernmental organisation that provides medium-range weather forecasts for its member countries and the wider international...

The balanced and stable positioning of a vessel in the water, where it is neither listing to one side nor pitching forward or aft. 

An "even...

A permanent loop formed at the end of a rope by interweaving its strands back into itself.

An eye splice is a fundamental ropework technique...

Sea area of the Met Office Shipping Forecast. Covers the sea around the Faroe Islands in the North Atlantic.

Covering waters around the Faroe...

A state in which the wind or weather conditions are favourable for navigation or sailing or to adjust or smooth the surface of a hull or...

Sea area of the Met Office Shipping Forecast. Spans the channel between the Orkney and Shetland Islands in the northern North Sea.

After Fair...

A device used to guide a line, rope, or cable, preventing it from chafing or snagging, and ensuring it runs smoothly along a desired path.

A...

Sea area of the Met Office Shipping Forecast. Located off Ireland’s southwest coast near Fastnet Rock.

After Fastnet Rock off Ireland’s SW...

A unit of length equal to six feet (1.8288 metres), commonly used to measure the depth of water.

A fathom is a traditional maritime unit of...

The International Maritime Signal Flag Foxtrot.

Meaning

I am disabled; communicate with me.

The phrase "feeling blue" is commonly used to describe sadness or melancholy, and its origins are often linked to nautical traditions.

A fender is a cushioning device used on boats and ships to prevent damage to the vessel or dock when they come into contact, particularly when...

A technique used to move a boat sideways across a flowing body of water without significant forward or backward motion relative to the...

A type of knot commonly used to create a secure stopper at the end of a rope, preventing it from slipping through a block, cleat, or...

Substitute or repeater flags allow messages with duplicate characters to be signalled without requiring multiple sets of flags.

Sea area of the Met Office Shipping Forecast. Covers Fisher Bank in the central North Sea, known for its rich fishing grounds.

Taking its name...

Sea area of the Met Office Shipping Forecast. Covers the Atlantic west of the Bay of Biscay.

Honoring Admiral Robert FitzRoy, founder of...

A system for conveying information at a distance through visual signals using hand-held flags.

The position of the flags encodes the...

To lay out or coil a line or rope in a flat, organised manner to prevent tangling or kinking.

Flaking is a crucial technique in maritime...

The process of neatly laying out a rope or line in a series of back-and-forth folds to prevent tangling and ensure it runs out smoothly when...

Flaking a sail is neatly folding or arranging it in parallel or accordion-like folds. This is typically done to store or stow the sail properly...

A pyrotechnic device used on boats to signal distress or indicate position, especially in emergencies.

Flares are an essential part of marine...

This shape represents the Letter F (Flag Semaphore) and the Number 6 (Flag Semaphore).

International Morse Code sequence representing the letter F.

The incoming or rising phase of the tide, during which seawater flows landward and the water level increases. 

A flood tide is the period...

The flat, triangular blade or arm of an anchor designed to dig into the seabed and provide holding power.

The term "fluke" in a marine context...

The rapid and uncontrolled movement of a sail or line due to a sudden change in wind or tension.

Flying out typically describes an event where...

A method of encoding information in a carrier wave by varying its frequency, commonly used in marine radio communications.

Frequency...

The lower edge of a sail, typically attached to the boom or deck of a sailing vessel.

The term foot refers to the bottom edge of a sail. On a...

The forward part of a vessel's deck, located towards the bow and often used for anchoring, mooring, or storage.

The foredeck is a critical...

A hatch located on the forward part of a vessel, typically providing access to the forepeak or forward compartments below deck.

A forehatch is...

Sea area of the Met Office Shipping Forecast. Located at the Firth of Forth, off eastern Scotland near Edinburgh.

Named after the Firth of Forth...

Sea area of the Met Office Shipping Forecast. Covers the central North Sea, northeast of the UK mainland.

Named for the Long Forties sandbank...

The section of a vessel that is located towards the bow, or front, of the ship.

Forward refers to the area or direction towards the bow...

Pronounced: FOKS-trot

The term for the letter F in the NATO Phonetic Alphabet.

A method of encoding information in a carrier wave by varying its frequency, commonly used in marine radio communications.

Frequency...

A Fuel collar is designed to fit around a refuelling hose to prevent any spillage or backsplash. This protects your boat and the environment.

A rotating mechanism at the base of a headsail furling system that enables the controlled rolling and unrolling of the sail around the...

A spar attached to a mast, used to support the upper edge of a fore-and-aft sail, such as a gaff rigged mainsail or topsail. 

A gaff is an...

A sailing rig where the sail is four-sided and controlled by a spar (the gaff) at its top, which is hoisted at an angle to the mast.

A gaff...

Beaufort Scale - Force 8 (Gale Force 8)

A gale refers to a strong wind between 34 to 40 knots (39 to 46 mph or 63 to 74 km/h) on the Beaufort...

The kitchen or cooking area on a ship or boat, typically compact and designed for efficient use of space.

Unlike a kitchen in a house, the...

The International Maritime Signal Flag Golf.

Meaning

I require a pilot.
By fishing vessels: I am hauling nets.
If appended by a Numeral...

A measure in marine navigation that quantifies the effect of satellite geometry on the accuracy of position determination. It is a factor used to...

A specialised resin-based coating applied to the surface of fibreglass boats to provide a smooth, durable, and protective outer layer.

Gelcoat...

A term that collectively refers to the three organisations responsible for maintaining maritime navigation aids—such as lighthouses, buoys, and...

A large foresail that overlaps the mainsail, commonly used on sailing yachts to improve speed and performance in light to moderate winds.

A...

A measure in marine navigation that quantifies the effect of satellite geometry on the accuracy of position determination. It is a factor used to...

Sea area of the Met Office Shipping Forecast. Located in the southeastern North Sea, off the coast of northern Germany and the...

A weather model developed by the National Centers for Environmental Prediction (NCEP) that provides global weather forecasts by simulating the...