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
- General Nautical Terminology, Nautical Topics, Parts of a Boat Daggerboard
A retractable underwater foil that slides up and down through a casing to resist sideways movement.
Unlike a pivoting centreboard, it normally...
More Details - General Nautical Terminology, Nautical Topics, Parts of a Boat, Safety, Signals & Communication Dan Buoy
A slender, upright floating marker used to make a position conspicuous on the water.
A dan buoy typically has a weighted or ballasted lower...
More Details - General Nautical Terminology, Nautical Topics, Mooring & Berthing, Parts of a Boat, Safety Danforth Anchor
A lightweight stock anchor with two broad pivoting flukes designed to penetrate suitable sand or mud.
The stock holds the crown and flukes at...
More Details - Abbreviation, General Nautical Terminology, Nautical Topics, Depths & Clearance, Navigation, Safety Dangerous Wreck
A charted wreck whose depth or clearance may present a hazard to surface navigation.
It is identified by the appropriate dangerous-wreck...
More Details - General Nautical Terminology, Nautical Topics, Parts of a Boat, Safety Davit
A lifting appliance fitted to a vessel or structure for lowering and recovering a boat or other load.
Davits commonly handle lifeboats, rescue...
More Details - General Nautical Terminology, Nautical Topics, Navigation, Safety, Signals & Communication Day Shape
A prescribed geometric shape displayed by day to indicate a vessel's status, operation or restriction under the collision regulations.
Balls,...
More Details - Courses, General Nautical Terminology, Nautical Topics, RYA, Navigation, Safety Day Skipper Practical (Motor)
An RYA practical motor-cruising course developing the ability to skipper short passages by day.
It covers preparation, pilotage, navigation,...
More Details - Courses, General Nautical Terminology, Nautical Topics, RYA, Navigation, Safety Day Skipper Practical (Sail)
An RYA practical sail-cruising course developing the ability to skipper short passages by day.
It combines pilotage, navigation, safety, crew...
More Details - Courses, General Nautical Terminology, Nautical Topics, RYA, Navigation, Safety Day Skipper Theory
An RYA shorebased navigation course providing the theory needed to plan and conduct coastal passages at day-skipper level.
It covers charts,...
More Details - General Nautical Terminology, Nautical Topics, Safety, Signals & Communication Code Flag Delta (D)
An International Code of Signals flag whose single-letter meaning is “Keep clear of me; I am manoeuvring with difficulty.”.
The Delta flag may...
More Details - General Nautical Terminology, Nautical Topics, Navigation Dead Reckoning (DR)
Estimating a vessel’s position by advancing a known position using course steered, speed through the water and elapsed time.
A dead-reckoning...
More Details - General Nautical Terminology, Nautical Topics, Organisation Deck Department
The shipboard department responsible for navigation, cargo work, deck maintenance and many seamanship operations.
It is normally led by the...
More Details - General Nautical Terminology, Nautical Topics, Parts of a Boat Deck Fill
A capped deck fitting through which a vessel’s fuel or fresh-water tank is filled.
The cap and surrounding label identify the tank served....
More Details - General Nautical Terminology, Nautical Topics, Navigation, Organisation, Safety Deck Officer
A certificated member of a ship’s deck department who performs navigational watches and deck-management duties.
Depending on rank, a deck...
More Details - General Nautical Terminology, Nautical Topics, Parts of a Boat Deck-stepped Mast
A mast whose heel is supported on the deck rather than continuing through it to a step below.
Compression loads are transferred through the...
More Details - Abbreviation, General Nautical Terminology, Nautical Topics, Navigation Deep-water Route (DW)
Abbreviated DW.
It is a route within defined limits that has been accurately surveyed for clearance of the seabed and submerged obstacles.
- General Nautical Terminology, Nautical Topics, Phonetic Alphabet, Signals & Communication Delta
The standard spoken code word for the letter D in the international radiotelephony spelling alphabet.
It is pronounced “DELL-tah” and is used...
More Details - General Nautical Terminology, Nautical Topics, Depths & Clearance, Navigation, Tides Delta
A depositional landform built where a river delivers sediment into a sea, lake or other relatively still body of water.
As flow slows,...
More Details - General Nautical Terminology, Nautical Topics, Mooring & Berthing, Parts of a Boat, Safety Delta Anchor
A proprietary-style fixed-shank plough anchor with a weighted, roughly triangular fluke designed to set quickly.
The original Delta design and...
More Details - General Nautical Terminology, Nautical Topics, Navigation Departure Plan
The detailed pilotage plan for leaving a berth, harbour or constrained waterway.
It covers unberthing, communications, tidal and weather...
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