Sailing terms and nautical glossary
Find clear definitions of sailing terms, boat parts, knots, navigation and nautical abbreviations. New to sailing? Start with the everyday words below, then explore the full glossary by subject or search for a term.
Sailing terms for beginners
Begin with port and starboard, bow, windward and leeward. Learn how sheets and halyards control sails, then explore points of sail, tacking and gybing.
For terms in context, read our beginner sailing vocabulary guide. Ready to practise on the water? Our first sailing course guide explains how to choose a starting route.
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TermDefinition
- Courses, General Nautical Terminology, Nautical Topics, RYA, Points of Sail, Safety Dinghy Sailing with Spinnakers
An RYA practical module teaching the rigging and use of conventional or asymmetric spinnakers in a dinghy.
It covers preparation, hoisting,...
More Details - Courses, General Nautical Terminology, Nautical Topics, RYA, Points of Sail, Safety Dinghy Seamanship Skills
An RYA advanced practical module developing versatile boat handling and problem-solving in a dinghy.
Exercises may include stopping, sailing...
More Details - Courses, General Nautical Terminology, Nautical Topics, RYA, Points of Sail, Safety Dinghy Start Racing
An RYA introductory racing course for sailors beginning to take part in organised dinghy races.
Training introduces starting, course sailing,...
More Details - General Nautical Terminology, Nautical Topics, Organisation, Signals & Communication Dip the Ensign
To lower a vessel’s ensign temporarily as a traditional maritime salute.
The ensign is lowered part-way or, where the arrangement permits,...
More Details - Abbreviation, General Nautical Terminology, Light Characteristic, Nautical Topics, Navigation, Signals & Communication Dir
A navigation light visible over a restricted sector and used to indicate a particular direction.
A directional light may mark a channel...
More Details - Abbreviation, General Nautical Terminology, Light Characteristic, Nautical Topics, Navigation, Signals & Communication Directional Light (Dir)
A navigation light visible over a restricted sector and used to indicate a particular direction.
A directional light may mark a channel...
More Details - Abbreviation, General Nautical Terminology, Nautical Topics, Navigation, Signals & Communication Directional Radiobeacon (RD)
Abbreviated RD on nautical charts.
Its transmitted signal provides directional information to a suitable receiver.
- General Nautical Terminology, Nautical Topics, Navigation, Signals & Communication Direction of Buoyage
The conventional direction used to determine the port-hand and starboard-hand sides of a buoyed route.
It is generally the direction followed...
More Details - Abbreviation, General Nautical Terminology, Nautical Topics, Navigation Discoloured Water (Discol)
A reported or observed patch whose colour differs from surrounding water, sometimes indicating shoaling, sediment or biological activity.
It...
More Details - General Nautical Terminology, Nautical Topics, Depths & Clearance, Parts of a Boat Displacement
The mass or weight of water displaced by a floating vessel, equal to the vessel’s total mass or weight in equilibrium.
Displacement is...
More Details - General Nautical Terminology, Nautical Topics, Parts of a Boat Displacement Vessel
A vessel supported primarily by hydrostatic buoyancy rather than dynamic planing lift throughout its normal speed range.
Its hull moves...
More Details - General Nautical Terminology, Nautical Topics, Depths & Clearance, Navigation Distance
The measured separation between two positions or features.
Marine distances are commonly expressed in nautical miles, where one international...
More Details - General Nautical Terminology, Nautical Topics, Navigation Distance Made Good
The straight-line distance between two positions actually reached by a vessel.
It measures net progress over the ground rather than the total...
More Details - General Nautical Terminology, Nautical Topics, Navigation Distance to Waypoint (DTW)
The calculated separation between a vessel’s current position and a selected waypoint.
A GNSS receiver or chartplotter normally updates this...
More Details - General Nautical Terminology, Nautical Topics, Safety, Signals & Communication Distress Flares
Pyrotechnic signals used to indicate distress, attract attention or help rescuers locate people or a vessel.
Rocket parachute flares provide a...
More Details - General Nautical Terminology, Nautical Topics, Safety Distress Message
A radio message giving the information needed to assist a vessel or person in grave and imminent danger.
It normally follows a distress alert...
More Details - General Nautical Terminology, Nautical Topics, Safety, Signals & Communication Distress Signal
A recognised signal indicating grave and imminent danger and a need for immediate assistance.
Maritime distress signals include specified...
More Details - General Nautical Terminology, Nautical Topics, Navigation, Parts of a Boat, Safety Dividers
A two-pointed hinged instrument used to transfer and measure distances on a chart.
The points can span two positions, step a distance along a...
More Details - General Nautical Terminology, Nautical Topics, Signals & Communication Letter D (Flag Semaphore)
A two-flag semaphore position representing the letter D.
The signaller holds one flag in each hand at the prescribed angles illustrated in the...
More Details - General Nautical Terminology, Nautical Topics, Signals & Communication Letter D (Morse Code)
The International Morse Code letter D, represented by dash dot dot (-..).
A dot lasts one signal unit and a dash three. Elements within this...
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