Exercises

Hazardous operations

North Atlantic Ocean · HYDROLANT 3375/16

What this record establishes

Archived notice · 2016-12-21 04:00Z

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 355/16 150043Z DEC 16.. Issued 2016-12-15 00:47Z. 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: North 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 North Atlantic Ocean →

Activity windows · 1 in this warning

opens (UTC)	closes (UTC)	local	length
2016-12-20 03:00Z	2016-12-21 03:00Z	—	24 h

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

issued: 2016-12-15 00:47Z
status: Archived notice
self-cancels: 2016-12-21 04:00Z
authority: NAVAREA V 355/16 150043Z DEC 16.
NAVAREA: NAVAREA V · named as the source of this relay
sea: North Atlantic Ocean
position: 5.012, -47.949
source: NGA MSI broadcast-warn JSON (archive, frozen 2024-05) · first seen 2026-08-17 13:38Z

Original warning text

WESTERN NORTH ATLANTIC.
BRAZIL-NORTH COAST.
HAZARDOUS OPERATIONS.
DNC 01.
1. HAZARDOUS OPERATIONS 200300Z TO 210300Z DEC
   IN AREA BOUND BY
   05-15N 047-27W, 04-44N 047-28W,
   04-46N 048-27W, 05-18N 048-25W.
2. CANCEL THIS MSG 210400Z DEC 16.

Reading this warning

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.
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.
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

66 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 20:20Z; 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.