Exercises

Hazardous operations 110900Z to 120400Z in area bound by 31-28.42S 049-14.02W, 31-13.60S 049-44.45W,…

South Atlantic Ocean · HYDROLANT 1739/23

What this record establishes

Archived notice · 2023-08-12 05:00Z

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 V 281/23 060019Z AUG 23.. Issued 2023-08-06 01:29Z. 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.

Current notices and reporting history in the South Atlantic Ocean →

Activity windows · 1 in this warning

opens (UTC)	closes (UTC)	local	length
2023-08-11 09:00Z	2023-08-12 04:00Z	—	19 h

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

issued: 2023-08-06 01:29Z
status: Archived notice
self-cancels: 2023-08-12 05:00Z
authority: NAVAREA V 281/23 060019Z AUG 23.
NAVAREA: NAVAREA V · named as the source of this relay
sea: South Atlantic Ocean
position: -32.182, -50.200
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, DNC 07.
1. HAZARDOUS OPERATIONS 110900Z TO 120400Z
   IN AREA BOUND BY
   31-28.42S 049-14.02W, 31-13.60S 049-44.45W,
   32-50.62S 051-08.20W, 33-10.30S 050-41.40W.
2. CANCEL THIS MSG 120500Z AUG 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

150 within 180 nm since 2003 · 3 in the last 12 months · 2 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

Hazardous operations 280900Z sep to 022100Z oct in area bound by 30-15.00S 050-06.75W, 30-15.00S 049-54.50W,…Exercises · 84.8 nm
Odas buoy temporarily established in 32-14.29S 051-58.16WNav aids · 89.9 nm
Hazardous operations 280800Z sep to 122200Z oct in area bound by 29-27.03S 049-32.03W, 29-30.53S 049-05.53W,…Exercises · 113.7 nm

Worldwide in the collected sources

32 military exercises listed in force · see all

Record snapshot 2026-09-26 17:16Z; 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.