Chart reference
The number of the nautical chart on which the reported position lies.
Many warnings name the chart the hazard falls on — "ENGLISH CHANNEL. CHART 36050." — so a navigator can find it quickly and mark it. Numbers can belong to U.S. (NGA or NOAA) charts, British Admiralty charts or national series; the warning usually does not say which, because the issuing service assumes its own.
A chart reference is not a correction to the chart. Permanent changes are published separately as Notices to Mariners; a navigational warning covers the time between a danger being reported and the chart being corrected, or the life of a temporary operation.
What the archive shows
16,455 messages in this archive use “Chart reference”, the earliest issued 1982-10-05 and the latest 2024-09-13. 20 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 1,126 messages. Collection is incomplete between 2024-05 and 2026-08-17, so 2024 is not comparable with fully collected years.
Nav aids accounts for 12,778 of 16,455 recorded messages (78%), the largest warning type group in this selection.
Located messages that use it fall in 88 sea areas; the most frequent are North Sea (2,587), South Atlantic Ocean (1,727) and North Atlantic Ocean (1,062).
Its use is spread fairly evenly through the year: the busiest month, January, has 1,600 messages and the quietest, April, 1,241.
By warning series: HYDROLANT 9,038, HYDROPAC 4,687, NAVAREA IV 1,453 and NAVAREA XII 1,037, and 2 more.
Messages using it, by year of issue
By month of issue, all years
Where it appears · 88 sea areas
In force now · 20
- NAVAREA IV 1125/24 · Nav aids · Caribbean Sea2024-09-13 · in force
GULF OF HONDURAS. BELIZE. CHART 28162. EAST SNAKE CAYE LIGHT 16-12.60N 088-30.20W UNLIT.
East snake caye light 16-12.60N 088-30.20W unlit → - NAVAREA IV 797/24 · Wrecks · Caribbean Sea2024-07-09 · in force
EASTERN CARIBBEAN SEA. GRENADINES. CHART 25001 DANGEROUS WRECK IN 12-35.75N 061-24.44W.
Grenadines → - NAVAREA IV 722/24 · Nav aids · Caribbean Sea2024-06-21 · in force
WESTERN CARIBBEAN SEA. BELIZE. CHART 26167. 1. SANDBORE CAY LIGHT 17-28.20N 087-29.50W UNLIT. 2. CANCEL NAVAREA IV 616/23.
Sandbore cay light 17-28.20N 087-29.50W unlit → - NAVAREA IV 356/23 · Nav aids · Caribbean Sea2023-03-27 · in force
WESTERN CARIBBEAN SEA. MEXICO. CHART 28190. TULUM LIGHT 20-12.68N 087-25.80W UNLIT.
Tulum light 20-12.68N 087-25.80W unlit → - NAVAREA XII 721/22 · Nav aids · North Pacific Ocean2022-09-27 · in force
EL SALVADOR. CHART 21524 MOORING BUOYS 13-35.23N 089-51.10W UNLIT.
El Salvador → - NAVAREA XII 720/22 · Nav aids · North Pacific Ocean2022-09-27 · in force
EASTERN NORTH PACIFIC. EL SALVADOR. CHART 12529. PUERTO DE LA UNION 16 BUOY 13-20.36N 087-48.99W UNLIT.
Puerto de la union 16 buoy 13-20.36N 087-48.99W unlit →
How it reads in recent messages
- NAVAREA IV 808/24 · Derelicts · Caribbean Sea2024-07-10
EASTERN CARIBBEAN SEA. MARTINIQUE. CHART 25001 DERELICT NINE METER S/V LIZA, WHITE HULL, PARTIALLY SUBMERGED AND AGROUND IN 14-37.58N…
Martinique → - NAVAREA IV 533/24 · Nav aids · Caribbean Sea2024-05-13
CARIBBEAN SEA. COLOMBIA. CHART 26060. CABO TIBURON LIGHT 08-40.60N 077-21.50W INOPERATIVE.
Cabo tiburon light 08-40.60N 077-21.50W inoperative → - NAVAREA IV 35/24 · Nav aids · North Atlantic Ocean2024-01-10
OLD BAHAMA CHANNEL. CUBA. CHART 26240, 26260. CAYO MOA LIGHT, FL W 10 SEC 14 METERS 10 MILES, ESTABLISHED IN 20-41.60N…
Cayo moa light, fl w 10 sec 14 meters 10 miles, established in 20-41.60N 074-54.40W → - NAVAREA IV 15/24 · Nav aids · Caribbean Sea2024-01-04
WESTERN CARIBBEAN SEA. PANAMA. CHART 26060. BUOY NO1 09-25.09N 079-49.50W DESTROYED.
Buoy NO1 09-25.09N 079-49.50W destroyed → - NAVAREA IV 1477/23 · Nav aids · Caribbean Sea2023-12-19
CARIBBEAN SEA. COLOMBIA. CHART 24480, 24490. WINDOW OF DREAMS LIGHT, OC W 4 SEC, 65 METERS, 20 MILES, ESTABLISHED IN…
Window of dreams light, oc w 4 sec, 65 meters, 20 miles, established in 11-00.09N 074-57.17W →
Earliest in the archive
- NAVAREA IV 2929/82 · Other1982-10-04
CHART 28015. SUB-SURFACE ACCOUSTIC CURRENT METERS ARRAY (DEPTH 100 METER) ESTABLISHED IN 21-38N.…
Sub-surface accoustic current meters array (depth 100 meter) established in 21-38N →
Often in the same message
Related terms
- DNC (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.
- Notice to Mariners
- The weekly publication of permanent chart corrections — the slower, permanent counterpart of a navigational warning.
- Position (degrees and minutes)
- How warnings write positions: degrees, a hyphen, then minutes, with N/S and E/W — 49-40.8N 003-43.8W.
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.