Glossary

An international standard developed by the International Hydrographic Organization (IHO) for the management, exchange, and interoperability of...

An international maritime treaty that sets minimum safety standards for ship construction, equipment, and operation. Its primary goal is to...

The Saffir-Simpson Scale is a classification system that categorises hurricanes based on their wind speed and potential for damage. It ranges...

A sail drive is a transmission system for a boat whose inboard engine has a horizontal output shaft. The sail drive's input shaft is, therefore,...

Sailing directions, also known as nautical directions or pilots, are publications that provide detailed information for navigating coastal and...

A designated storage space aboard a vessel where sails and related equipment are kept when not in use.

A sail locker is an essential feature...

The concentration of dissolved salts in water, typically measured in parts per thousand (ppt) or practical salinity units (PSU).

Salinity is a...

The coordinated efforts undertaken to locate and assist individuals in distress or imminent danger, typically at sea, and to bring them to...

An emergency device that responds to radar signals by transmitting a series of pulses to help rescuers locate a vessel or liferaft in...

A German boating licence required for operating recreational motorboats and sailing vessels above certain power or length limits in German...

A German boating licence required for operating recreational motorboats and sailing vessels on inland waterways. 

The Sportbootführerschein...

A German boating licence required for operating recreational motorboats and sailing vessels with an engine of more than 15 horsepower in coastal...

The International Maritime Signal Flag Sierra.

Meaning

I am operating astern propulsion.
If appended with a Numeral Pennant, Speed...

An opening in the side of a ship or boat, designed to allow water on deck to drain overboard.

In maritime terminology, a scupper is an...

A device, typically a canvas or synthetic fabric drogue, deployed in the water to stabilise a vessel by creating drag and reducing drift in rough...

A cooling wind that blows from the sea towards the land, typically occurring during the daytime due to temperature differences between the land...

The ability of a person to maintain balance and move steadily on a vessel in motion, particularly in rough seas.

Sealegs is a term deeply...

The coordinated efforts undertaken to locate and assist individuals in distress or imminent danger, typically at sea, and to bring them to...

An emergency device that responds to radar signals by transmitting a series of pulses to help rescuers locate a vessel or liferaft in...

A location where tidal information is derived by applying corrections to data from a nearby Standard Port. 

A secondary port is a coastal...

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

Occasionally a light may not be visible through 360 degrees, or it may shine different colours depending on where it is viewed from. In this...

A maritime safety message broadcast over radio to convey important but non-urgent navigational or weather-related information.

Sécurité is a...

A signalling system used to convey information at a distance by means of visual signals, typically using flags or lights.

Semaphore is a...

A type of boat or ship designed to operate efficiently in both displacement and planing modes, offering a balance between speed and fuel...

The direction which a current flows in a body of water.

In marine navigation, understanding the set of a current is crucial for plotting an...

The process of securing a boat in a stationary position by deploying and embedding an anchor into the seabed.

When a mariner 'sets anchor',...

To "set sail" means to begin a voyage or journey by sea, typically by hoisting the sails of a sailboat or ship to catch the wind and propel the...

A U-shaped metal fitting with a pin or bolt across the opening, used in marine applications to connect ropes, chains, or other fittings...

Shaft drive refers to a method of transferring power from an engine to a boat's propeller. In this system, a driveshaft connects the engine to...

The part of an anchor that digs into the seabed to secure the boat in place. 

The Shank refers to the long, vertical part of an anchor that...

Sea area of the Met Office Shipping Forecast. Lies off the west coast of Ireland at the mouth of the River Shannon.

From the Shannon Estuary...

A line or rope used to control the angle of a sail relative to the wind.

In sailing, a sheet is an essential part of the rigging system and...

A maritime weather broadcast provided by the UK Met Office, offering vital information on sea conditions, wind, and visibility for seafarers in...

A designated route in a body of water that is regularly used by commercial and cargo vessels to ensure safe and efficient maritime...

To reduce the amount of sail area exposed to the wind, typically to maintain control and safety in strong winds.

Shortening sail is a sailing...

A strong, fixed line or wire that supports a sailing vessel's mast laterally, running from the mast to the sides of the hull or to...

Pronounced: see-AIR-rah

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

A skeg is a small fin or projection on the bottom of a boat's hull, typically near the stern. It helps to provide directional stability and...

A German recreational boating licence required for operating yachts under sail or power in coastal waters up to 12 nautical miles...

A method of reefing a boomed sail where the sail is flaked down on top of the boom. This allows the sail to be reefed by pulling a line attached...

To loosen a line, rope, or sheet on a vessel, reducing tension.

A term commonly used in maritime contexts to describe the act of easing or...

The short period of still water occurring at the turn of the tide, when the tidal current changes direction and its speed is minimal.

Slack...

Flag semaphore indicating the letter S.

International Morse Code sequence representing the letter S.

Ropes or lines used to temporarily secure a vessel to a dock or mooring point in such a way that they can be released from onboard without...

The act of releasing a vessel's mooring lines in a controlled manner, allowing it to depart from a berth or dock without assistance from shore...

A sloped structure or ramp leading into the water, used for launching, retrieving, or repairing boats and ships. 

A slipway, also known as a...

Electronic navigation standards for commercial vessels less than 24m .

Equipment meeting the requirements of this performance standard is...

A set of internationally agreed-upon phrases used to ensure clear, concise, and unambiguous communication at sea, particularly between vessels...

The actual velocity of a vessel relative to the Earth's surface, accounting for the effects of currents, tides, and other environmental...

An international maritime treaty that sets minimum safety standards for ship construction, equipment, and operation. Its primary goal is to...

Chapter V of SOLAS (Safety of life at Sea) refers to the Safety of Navigation for all vessels at sea.

SOLAS V for pleasure craft

SOLAS V...

Sea area of the Met Office Shipping Forecast. Covers Sole Bank in the eastern Bay of Biscay off the French coast.

From the Sole Bank, famed...

The flat, horizontal planks or panels that form the flooring of a boat's interior, typically installed over the bilge area to provide a stable...

The universally recognised distress signal used in maritime communication to indicate an emergency requiring immediate assistance.

The German...

Sea area of the Met Office Shipping Forecast. Located southeast of Iceland in the North Atlantic.

Southeast Iceland covers waters renamed from...

Sea area of the Met Office Shipping Forecast. Situated in the North Sea, south of Utsira Island off the west coast of Norway.

Also named for...

This shape indicates a space, usually between words. The same shape is also used for Rest (Flag Semaphore) & Ready (Flag Semaphore).

Any long, sturdy pole or beam used on a ship to support sails, rigging, or other equipment. Spars are typically made of wood, metal, or composite...

The actual velocity of a vessel relative to the Earth's surface, accounting for the effects of currents, tides, and other environmental...

The velocity at which a vessel moves relative to the water it is travelling through, excluding the effects of current or tidal flow.

Speed...

A large, lightweight, and often colourful sail designed for use when sailing downwind, typically set forward of the mainsail to maximise speed...

A spar used on sailing vessels to control one clew of a spinnaker sail when sailing downwind.

A spinnaker pole is a key piece of equipment...

A method of joining two ropes or lines by interweaving their strands to form a strong, secure connection.

A splice is a fundamental technique...

A German boating licence required for operating recreational motorboats and sailing vessels above certain power or length limits in German...

A German boating licence required for operating recreational motorboats and sailing vessels on inland waterways. 

The Sportbootführerschein...

A German boating licence required for operating recreational motorboats and sailing vessels with an engine of more than 15 horsepower in coastal...

A German recreational boating licence required for operating yachts under sail or power in coastal waters up to 12 nautical miles...

A protective canvas or fabric structure, often supported by a metal frame, installed over the companionway of a boat to shield the cockpit and...

Horizontal or angled spars attached to a yacht's mast, used to hold the shrouds away from the mast and improve the stability and tension of the...