Exercises

Gunnery exercises 2300Z to 0900Z daily 25 thru 27 apr in area bound by 37-44-55N 124-05-10E, 37-44-55N…

Yellow Sea · HYDROPAC 1212/21

What this record establishes

Archived notice · 2021-04-28 10:00Z

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 137/21 211133Z APR 21.. Issued 2021-04-21 11:35Z. 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: Yellow 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 Yellow Sea →

Activity windows · 3 in this warning

opens (UTC)	closes (UTC)	local	length
2021-04-25 23:00Z	2021-04-26 09:00Z	—	10 h
2021-04-26 23:00Z	2021-04-27 09:00Z	—	10 h
2021-04-27 23:00Z	2021-04-28 09:00Z	—	10 h

Parsed from the warning text; outside these windows the area is normally not active, but the warning stays in force until cancelled.

issued: 2021-04-21 11:35Z
status: Archived notice
self-cancels: 2021-04-28 10:00Z
authority: NAVAREA XI 137/21 211133Z APR 21.
NAVAREA: NAVAREA XI · named as the source of this relay
sea: Yellow Sea
position: 37.626, 124.349
source: NGA MSI broadcast-warn JSON (archive, frozen 2024-05) · first seen 2026-08-17 13:38Z

Original warning text

YELLOW SEA.
DNC 23.
1. GUNNERY EXERCISES 2300Z TO 0900Z DAILY
   25 THRU 27 APR IN AREA BOUND BY
   37-44-55N 124-05-10E, 37-44-55N 124-36-40E,
   37-30-10N 124-36-40E, 37-30-14N 124-05-10E.
2. CANCEL THIS MSG 281000Z APR 21.

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.
Gunnery and live firing: Naval or coastal guns firing into a sea area for practice, at stated times.
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.
Date-time group (DTG): A compact UTC timestamp — day, hour and minute followed by Z — such as 201500Z for the 20th at 15:00 UTC.

All warning terms →

Collected reports in this area · military exercises

1356 within 180 nm since 2000 · 0 in the last 12 months · 0 listed in force now

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

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

28 military exercises listed in force · see all

Record snapshot 2026-10-01 17:35Z; 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.