Gpa jamming exercises 1400Z to 1600Z daily 23 thru 25 mar in area within 30 miles of 52-08.5N 004-34.3W
Irish Sea and St. George's Channel · HYDROLANT 814/21
What this record establishes
Archived notice · 2021-03-25 17:00Z
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) · WZ 330/21 230842Z MAR 21.. Issued 2021-03-23 09:20Z. 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.
Related notices and cancellation links
Current notices and reporting history in the Irish Sea and St. George's Channel →
Activity windows · 3 in this warning
| opens (UTC) | closes (UTC) | local | length |
|---|---|---|---|
| 2021-03-23 14:00Z | 2021-03-23 16:00Z | — | 2 h |
| 2021-03-24 14:00Z | 2021-03-24 16:00Z | — | 2 h |
| 2021-03-25 14:00Z | 2021-03-25 16:00Z | — | 2 h |
Parsed from the warning text; outside these windows the area is normally not active, but the warning stays in force until cancelled.
- issued
- 2021-03-23 09:20Z
- status
- Archived notice
- self-cancels
- 2021-03-25 17:00Z
- authority
- WZ 330/21 230842Z 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 THRU 25 MAR IN AREA WITHIN 30 MILES OF 52-08.5N 004-34.3W. 2. CANCEL HYDROLANT 812/21. 3. CANCEL THIS MSG 251700Z 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.
- Cancellation reference
- A line that cancels an earlier warning by its number, such as CANCEL HYDROLANT 1085/12.
- HYDROLANT
- The U.S. long-range warning series for Atlantic waters outside NAVAREA IV, including the eastern Atlantic, the Mediterranean and adjoining seas.
- 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.
Collected reports in this area · other warnings
216 within 180 nm since 1999 · 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.
- Fishing gear, marked by buoys, abandoned in 53-30.10N 004-12.70W2024-04-22
- Fishing gear, marked by buoys, abandoned in 50-12.57N 004-36.15W2024-01-02
- Cgoc falmouth mf dsc and r/t services at scilly isle site 49-55.7N 006-18.2W unreliable2023-11-25
- 14 meter long tree adrift in vicinity 53-39.90N 006-02.80W at 150840Z aug2023-08-15
- Cgoc falmouth mf r/t services at scilly isle site in 49-55.70N 006-18.20W at reduced power2023-07-18
- Large wooden objects reported adrift in vicinity 51-29.30N 007-24.20W at 261629Z jun2023-06-26
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
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.