Other

Gpa jamming exercises 1400Z to 1600Z daily 23 and 24 mar in area within 30 miles of 52-08.5N 004-34.3W

Irish Sea and St. George's Channel · HYDROLANT 812/21

What this record establishes

Archived notice · 2021-03-23 09:20Z

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) · WZ 327/21 230130Z MAR 21.. Issued 2021-03-23 04:21Z. 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
Irish Sea and St. George's Channel. The parsed report position is 52.142, -4.572 with a 30.0 nm radius. It is a position in the source message, not a live location. Check the original wording for limits and qualifications.

Current notices and reporting history in the Irish Sea and St. George's Channel →

issued
2021-03-23 04:21Z
status
Archived notice
self-cancels
2021-03-24 17:00Z
authority
WZ 327/21 230130Z MAR 21.
issued by
WZ
sea
Irish Sea and St. George's Channel
position
52.142, -4.572 · r 30.0 nm
source
NGA MSI broadcast-warn JSON (archive, frozen 2024-05) · first seen 2026-08-17 13:38Z

Original warning text

CARDIGAN BAY.
SAINT GEORGES CHANNEL.
WALES.
DNC 20.
1. GPA JAMMING EXERCISES 1400Z TO 1600Z DAILY
   23 AND 24 MAR IN AREA WITHIN 30 MILES OF
   52-08.5N 004-34.3W.
2. CANCEL THIS MSG 241700Z MAR 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.
GNSS / GPS
Satellite positioning — GPS and other systems — and the testing, jamming and interference that make it unreliable in an area.
Within a radius of
A circular area — every position within a stated distance of a point.
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 · other warnings

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

99
00
05
10
15
20
24

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

21 other warnings listed in force · see all

Record snapshot 2026-10-02 22:27Z; source collection times vary.

Other

Everything the classifier did not place elsewhere. All current other warnings →

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.