Glossary
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TermDefinition
- General Nautical Terminology, Nautical Topics, Organisation, Weather (Meteorology) National Meteorological Service
A country's official organisation for observing, forecasting and warning about weather and related environmental conditions.
It operates...
More Details - General Nautical Terminology, Nautical Topics, Navigation, Organisation, Weather (Meteorology) National Oceanic and Atmospheric Administration (NOAA)
A United States government agency responsible for science and services relating to weather, climate, oceans and coasts.
Usually abbreviated to...
More Details - General Nautical Terminology, Nautical Topics, Organisation, Signals & Communication NATO
An intergovernmental political and military alliance founded in 1949 for the collective defence of its members.
NATO provides a forum for...
More Details - General Nautical Terminology, Nautical Topics, Safety, Signals & Communication NATO Phonetic Alphabet
A standard set of code words used to transmit letters clearly when speech may be misunderstood.
In marine radiotelephony, letters are spoken...
More Details - General Nautical Terminology, Nautical Topics, Navigation, Organisation Nautical Almanac
An annual publication of predicted astronomical data used for celestial navigation and related calculations.
It tabulates the Greenwich Hour...
More Details - General Nautical Terminology, Nautical Topics, Depths & Clearance, Navigation Nautical Chart
An official or purpose-produced representation of navigable waters and adjoining areas for marine navigation.
A nautical chart can show...
More Details - Abbreviation, General Nautical Terminology, Light Characteristic, Nautical Topics, Navigation, Signals & Communication Nautical Chart Light Characteristic
A compact description of a light.
For example, Fl(2)R.10s15m12M means two red flashes in each 10-second period, a focal height of 15 metres...
More Details - General Nautical Terminology, Nautical Topics, Navigation Nautical Mile
A unit of distance defined as exactly 1,852 metres.
The international nautical mile is approximately 1.1508 statute miles and underlies the...
More Details - Abbreviation, General Nautical Terminology, Light Characteristic, Nautical Topics, Navigation, Signals & Communication Nautical Mile in a Light Description (M)
The abbreviation M denotes nautical miles in the nominal range of a charted light.
For example, 12M means a nominal range of 12 nautical...
More Details - General Nautical Terminology, Nautical Topics, Navigation Navigational Warning
An official notice of a newly reported or temporary hazard significant to safe navigation.
Warnings may concern failed aids, wrecks, military...
More Details - Abbreviation, General Nautical Terminology, Light Characteristic, Nautical Topics, Navigation, Parts of a Boat, Safety, Signals & Communication Navigation Lights (Lts)
Lights displayed by a vessel to indicate its presence, aspect, type, size or operational status to other vessels.
Common navigation lights...
More Details - General Nautical Terminology, Nautical Topics, Navigation, Safety, Signals & Communication NAVTEX
An international automated radio service that broadcasts maritime safety information to ships in coastal and sea areas.
NAVTEX transmits...
More Details - General Nautical Terminology, Nautical Topics, Navigation, Safety, Signals & Communication NAVTEX
An international automated radio service that broadcasts maritime safety information to ships in coastal and sea areas.
NAVTEX transmits...
More Details - General Nautical Terminology, Nautical Topics, Safety, Signals & Communication Code Flag November (N)
An International Code of Signals flag whose single-letter meaning is “No—a negative response.”.
The November flag may be displayed alone to...
More Details - General Nautical Terminology, Nautical Topics, Navigation, Signals & Communication NDB
A radio beacon that transmits essentially equally in all horizontal directions for direction-finding or identification.
A receiver with an...
More Details - General Nautical Terminology, Nautical Topics, Depths & Clearance, Navigation, Tides Neap Range
The difference in height between mean high water neaps and mean low water neaps.
It represents the average tidal range around neap tides at a...
More Details - General Nautical Terminology, Nautical Topics, Depths & Clearance, Navigation, Tides Neap Tide
A period in the astronomical tidal cycle when the range between successive high and low waters is relatively small.
Neaps generally occur near...
More Details - General Nautical Terminology, Nautical Topics, Sea State & Waves, Weather (Meteorology) Near Gale
A Beaufort force 7 wind, with a mean speed of 28 to 33 knots.
Near gale is the formal descriptive term immediately below gale on the Beaufort...
More Details - General Nautical Terminology, Nautical Topics, Navigation, Organisation, Safety NLB
The General Lighthouse Authority responsible for aids to navigation in Scotland and the Isle of Man.
The Northern Lighthouse Board provides...
More Details - General Nautical Terminology, Nautical Topics, Signals & Communication Letter N (Flag Semaphore)
A two-flag semaphore position representing the letter N.
The signaller holds one flag in each hand at the prescribed angles illustrated in the...
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