DNC (Digital Nautical Chart)
Also written: Digital Nautical Chart
A reference to one of the regions of NGA's Digital Nautical Chart, used to tell the reader which charts a warning affects.
The Digital Nautical Chart is the vector chart database the U.S. National Geospatial-Intelligence Agency produces, primarily for the U.S. Navy. It is divided into numbered geographic regions, and NGA warnings end with a line such as "DNC 17" naming the region whose charts the warning affects.
The DNC line is the most common single element of NGA warnings in force: most HYDROLANT, HYDROPAC and NAVAREA IV and XII messages carry one. It says nothing about the hazard itself, but it is a quick way to tell which part of the world a telegram belongs to.
What the archive shows
75,743 messages in this archive use “DNC (Digital Nautical Chart)”, the earliest issued 2004-08-06 and the latest 2026-09-11. 57 of them are in force in the latest lists we collected. A hazard reported again and again counts once per message.
The largest yearly count is 2017, with 8,982 messages. Collection is incomplete between 2024-05 and 2026-08-17, so 2024, 2025 and 2026 are not comparable with fully collected years.
Exercises accounts for 15,922 of 75,743 recorded messages (21%), the largest warning type group in this selection.
Located messages that use it fall in 96 sea areas; the most frequent are South Atlantic Ocean (7,559), North Pacific Ocean (3,875) and South China Sea (3,859).
Its use is spread fairly evenly through the year: the busiest month, November, has 6,889 messages and the quietest, July, 5,718.
By warning series: HYDROPAC 39,396, HYDROLANT 33,454, HYDROARC 2,847 and NAVAREA IV 32, and 1 more.
Messages using it, by year of issue
By month of issue, all years
Where it appears · 96 sea areas
- South Atlantic Ocean 7,559
- North Pacific Ocean 3,875
- South China Sea 3,859
- North Atlantic Ocean 3,604
- South Pacific Ocean 3,282
- Mediterranean Sea - Eastern Basin 3,031
- Arabian Sea 2,805
- Southern Ocean 2,739
- Indian Ocean 2,488
- Bay of Bengal 2,199
- Black Sea 2,029
- North Sea 1,877
In force now · 57
- HYDROPAC 808/26 · Nav aids · South Pacific Ocean2026-03-17 · in force
SOUTH PACIFIC. FIJI. DNC 06. NORTH OVALAU ISLAND LIGHT 17-33.81S 178-50.92E UNLIT.
North ovalau island light 17-33.81S 178-50.92E unlit → - HYDROPAC 627/26 · Nav aids · Gulf of Oman2026-03-03 · in force
ARABIAN SEA. GULF OF OMAN. STRAIT OF HORMUZ. U.A.E. DNC 10. GPS, GNSS, AND AIS INTERFERENCE REPORTED IN VICINITY OF FUJAIRAH (25-07.33N…
GPS, GNSS, and AIS interference reported in vicinity of fujairah (25-07.33N 056-20.05E) → - HYDROPAC 622/26 · Nav aids · South Pacific Ocean2026-03-02 · in force
SOUTH PACIFIC. FIJI. DNC 06. UDU POINT LIGHT IN 16-07.53S 179-57.21W UNLIT.
Udu point light in 16-07.53S 179-57.21W unlit → - HYDROPAC 598/26 · Nav aids · Persian Gulf2026-02-28 · in force
PERSIAN GULF. IRAN. DNC 10. ODAS BUOY RELOCATED TO 28-49.63N 050-42.93E.
Odas buoy relocated to 28-49.63N 050-42.93E → - HYDROPAC 540/26 · Nav aids · Persian Gulf2026-02-23 · in force
PERSIAN GULF. QATAR. DNC 10. WAVE RIDER BUOY, FL 5 Y 10 SEC, TEMPORARILY ESTABLISHED IN 26-39.57N 051-57.22E.
Wave rider buoy, fl 5 y 10 sec, temporarily established in 26-39.57N 051-57.22E → - HYDROPAC 473/26 · Wrecks · Persian Gulf2026-02-16 · in force
U.A.E. DNC 10. 12.9 METER DEPTHS REPORTED IN BOROUGE CHANNEL 24-09.00N 052-45.20E.
12.9 meter depths reported in borouge channel 24-09.00N 052-45.20E →
How it reads in recent messages
- HYDROLANT 1800/26 · Nav aids · South Atlantic Ocean2026-09-11
SOUTH ATLANTIC. BRAZIL. DNC 01. CHAPEU VIRADO LIGHT 01-08.12S 048-28.14W. UNLIT.
Chapeu virado light 01-08.12S 048-28.14W → - HYDROPAC 766/26 · Cable ops · Arabian Sea2026-03-13
ARABIAN SEA. GULF OF KHAMBHAT. INDIA. DNC 03. 1. PIPELINE OPERATIONS 15 MAR THRU 30 APR BY M/V EMERALD IN VICINITY OF TRACKLINE…
Pipeline operations 15 mar thru 30 apr by M/V emerald in vicinity of trackline joining 20-36.02N 072-02.23E,… → - HYDROLANT 492/26 · Nav aids · South Atlantic Ocean2026-03-13
SOUTH ATLANTIC. BRAZIL. DNC 01. 1. BARRA DE ITABAPOANA LIGHT 21-18.80S 040-57.90W UNLIT UNTIL 08 SEP 26. 2. CANCEL…
Barra de itabapoana light 21-18.80S 040-57.90W unlit until 08 sep 26 → - HYDROPAC 692/26 · Wrecks · Arabian Sea2026-03-09
ARABIAN SEA. INDIA. DNC 03. IFB SEA PRINCESS SANK IN 19-04.90N 072-44.90E.
Ifb sea princess sank in 19-04.90N 072-44.90E → - HYDROPAC 683/26 · Nav aids · South Pacific Ocean2026-03-08
SOUTH PACIFIC. DNC 07. DART II BUOY 20-41.74S 073-16.23W TEMPORARILY REMOVED.
Dart II buoy 20-41.74S 073-16.23W temporarily removed → - HYDROLANT 453/26 · Nav aids · South Atlantic Ocean2026-03-07
SOUTH ATLANTIC. BRAZIL. DNC 01. 1. CAETE LIGHT 00-49.02S 046-36.86W DESTROYED. 2. CANCEL THIS MSG 030001Z SEP 26.
Caete light 00-49.02S 046-36.86W destroyed → - HYDROLANT 434/26 · Nav aids · South Atlantic Ocean2026-03-05
SOUTH ATLANTIC. BRAZIL. DNC 01. 1. PONTA DA GALHETA LIGHT 27-34.55S 048-24.99W UNLIT UNTIL 31 AUG. 2. CANCEL THIS MSG…
Ponta da galheta light 27-34.55S 048-24.99W unlit until 31 aug →
Earliest in the archive
- HYDROPAC 1272/04 · Other2004-08-05
…AND IS ALSO AVAILABLE OVER THE NGA GATEWAY: A. SIPRNET: SPS.STL.NGA.SMIL.MIL/PRODUCTS/DNC1/INDEX.HTM B. JWICS: JWS.STL.NGA.IC.GOV/PRODUCTS/DNC1/INDEX.HTM 3. AUTHORIZED USERS OF…
The distribution of DNC is authorized to U.S →
Often in the same message
Related terms
- Chart reference
- The number of the nautical chart on which the reported position lies.
- HYDROLANT
- The U.S. long-range warning series for Atlantic waters outside NAVAREA IV, including the eastern Atlantic, the Mediterranean and adjoining seas.
- HYDROPAC
- The U.S. long-range warning series for the Pacific outside NAVAREA XII and for the Indian Ocean, Persian Gulf and adjoining seas.
Counts cover the messages in this archive that use the term, recounted 2026-09-24; see coverage for what is collected and since when. Not for navigation — follow official NAVAREA and coastal broadcasts.