Exercises

Hazardous operations 260001Z apr to 130001Z may in area bound by 26-59.82S 046-22.87W, 26-59.82S 047-54.87W,…

South Atlantic Ocean · HYDROLANT 857/23

What this record establishes

Archived notice · 2023-04-21 04:03Z

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 V 127/23 210136Z APR 23.. Issued 2023-04-21 03:41Z. 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 Atlantic Ocean. The map shows an area described by the warning; the listed coordinate is its representative center. Check the original wording for limits and qualifications.

Related notices and cancellation links

Current notices and reporting history in the South Atlantic Ocean →

Activity windows · 1 in this warning

opens (UTC)closes (UTC)locallength
2023-04-26 00:01Z2023-05-13 00:01Z—408 h

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

issued
2023-04-21 03:41Z
status
Archived notice
self-cancels
2023-05-13 01:01Z
authority
NAVAREA V 127/23 210136Z APR 23.
NAVAREA
NAVAREA V · named as the source of this relay
sea
South Atlantic Ocean
position
-27.874, -47.147
source
NGA MSI broadcast-warn JSON (archive, frozen 2024-05) · first seen 2026-08-17 13:38Z

Original warning text

WESTERN SOUTH ATLANTIC.
BRAZIL.
DNC 01.
1. HAZARDOUS OPERATIONS
   260001Z APR TO 130001Z MAY
   IN AREA BOUND BY
   26-59.82S 046-22.87W, 26-59.82S 047-54.87W,
   28-45.07S 047-54.87W, 28-45.07S 046-22.68W.
2. CANCEL THIS MSG 130101Z MAY 23.

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.
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.
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

245 within 180 nm since 2003 · 0 in the last 12 months · 0 listed in force now

03
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

28 military exercises listed in force · see all

Record snapshot 2026-10-01 23:40Z; 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.