Exercises

Hazardous operations in progress until 31 dec in areas bound by: a. 24-11-56N 119-45-36E, 24-11-34N…

South China Sea · HYDROPAC 940/21

What this record establishes

Archived notice · 2022-01-01 00:01Z

This notice comes from the historical archive. Its archived status does not establish when or how the reported situation ended.

Source and dates
NGA MSI broadcast-warn JSON (archive, frozen 2024-05) · NAVAREA XI 102/21 251736Z MAR 21.. Issued 2021-03-25 19:00Z. First collected 2026-08-17 13:38Z; last seen in collection 2026-08-17 15:46Z. Collection dates record ingestion, not a new incident or a fresh field observation.
Location covered
South China Sea. The map shows an area described by the warning; the listed coordinate is its representative center. Check the original wording for limits and qualifications.

Current notices and reporting history in the South China Sea →

issued
2021-03-25 19:00Z
status
Archived notice
authority
NAVAREA XI 102/21 251736Z MAR 21.
NAVAREA
NAVAREA XI · named as the source of this relay
sea
South China Sea
position
24.157, 120.009
source
NGA MSI broadcast-warn JSON (archive, frozen 2024-05) · first seen 2026-08-17 13:38Z

Original warning text

TAIWAN STRAIT.
TAIWAN.
DNC 23.
1. HAZARDOUS OPERATIONS IN PROGRESS UNTIL 31 DEC
   IN AREAS BOUND BY:
   A. 24-11-56N 119-45-36E, 24-11-34N 119-54-22E,
      24-08-27N 119-52-15E.
   B. 24-08-34N 119-49-50E, 24-11-38N 119-45-23E,
      24-11-34N 119-54-22E,
   C. 24-11-13N 120-02-17E, 24-06-54N 119-58-57E,
      24-07-09N 119-51-22E.
   D. 24-12-34N 120-03-20E, 24-11-02N 120-04-43E,
      24-08-35N 120-16-16E, 24-08-31N 120-16-50E,
      24-08-18N 120-18-03E, 24-07-34N 120-20-45E.
   E. 24-08-02N 120-16-47E, 24-08-03N 120-16-39E,
      24-08-02N 120-16-12E, 24-08-01N 120-16-02E,
      24-10-30N 120-04-24E, 24-09-34N 120-01-00E.
2. CANCEL THIS MSG 01 JAN 22.

Reading this warning

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.
Hazardous operations
NGA's heading for activities that make an area dangerous — most often rocket launches, space debris and weapons firings, and some open-ended danger areas.
Area bound by
Introduces a list of positions that are the corners of an area — the polygon the warning applies to.
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.
CANCEL THIS MSG
The warning's own expiry: a line telling the reader when the message cancels itself.

All warning terms →

Collected reports in this area · military exercises

797 within 180 nm since 1999 · 0 in the last 12 months · 0 listed in force now

99
00
05
10
15
20
23

Counts include repeat notices about the same situation. NGA archive coverage ends 2024-05; live collection began 2026-08-17. The period between them is incomplete. An empty year is not evidence that no hazards occurred.

Month of issue in the collected archive

J
F
M
A
M
J
J
A
S
O
N
D

All available years combined. Uneven collection and repeat bulletins affect these counts; this chart does not measure the seasonality or probability of incidents.

Nearby notices listed in force · within 120 nm

No other collected notice is currently listed in force within this radius. This does not establish safe conditions.

Worldwide in the collected sources

32 military exercises listed in force · see all

Record snapshot 2026-09-27 16:06Z; source collection times vary.

Exercises

Gunnery, firing and naval exercise areas. All current military exercises →

Not for navigation. This is a re-rendering of an official navigational warning for awareness; mariners must use official NAVAREA broadcasts and their national MSI service.