Exercises

Hazardous operations

North Atlantic Ocean · HYDROLANT 855/15

What this record establishes

Archived notice · 2015-04-13 16:42Z

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 N 346/15 110014Z APR 15.. Issued 2015-04-11 02:55Z. 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.

Related notices and cancellation links

Current notices and reporting history in the North Atlantic Ocean →

Activity windows · 1 in this warning

opens (UTC)closes (UTC)locallength
2015-04-15 18:30Z2015-05-15 22:37Z—724 h 07

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

issued
2015-04-11 02:55Z
status
Archived notice
self-cancels
2015-05-15 23:37Z
authority
NAVAREA V N 346/15 110014Z APR 15.
NAVAREA
NAVAREA V · named as the source of this relay
issued by
NAVAREA V N
sea
North Atlantic Ocean
position
5.184, -47.342
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 151830Z APR TO 152237Z MAY
   IN AREAS BOUND BY:
   A. 05-15N 045-40W, 05-00N 045-40W,
      05-03N 047-25W, 05-18N 047-24W.
   B. 05-27N 047-32W, 04-58N 047-33W,
      04-58N 048-33W, 05-28N 048-33W.
2. CANCEL THIS MSG 152337Z MAY 15.

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

57 within 180 nm since 2000 · 0 in the last 12 months · 0 listed in force now

00
05
10
15
17

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

30 military exercises listed in force · see all

Record snapshot 2026-09-25 19:21Z; 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.