Surveys

Underwater operations 010000Z aug until further notice by M/V 7 waves in area bound by 23-53.00N 016-48.00W,…

North Atlantic Ocean · HYDROLANT 1688/23

What this record establishes

Archived notice · 2023-09-07 09:38Z

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 II 197/23 271501Z JUL 23.. Issued 2023-07-27 15:12Z. 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 →

issued
2023-07-27 15:12Z
status
Archived notice
authority
NAVAREA II 197/23 271501Z JUL 23.
NAVAREA
NAVAREA II · named as the source of this relay
sea
North Atlantic Ocean
position
22.442, -16.918
source
NGA MSI broadcast-warn JSON (archive, frozen 2024-05) · first seen 2026-08-17 13:38Z

Original warning text

EASTERN NORTH ATLANTIC.
MAURITANIA.
DNC 01.
UNDERWATER OPERATIONS 010000Z AUG UNTIL
FURTHER NOTICE BY M/V 7 WAVES IN AREA BOUND BY
23-53.00N 016-48.00W, 23-40.00N 015-51.00W,
23-26.00N 015-56.00W, 21-59.00N 016-59.00W,
20-49.00N 017-10.00W, 20-10.00N 017-42.00W,
22-04.00N 017-27.00W, 22-59.00N 017-11.00W.
WIDE BERTH REQUESTED.

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.
Underwater operations
Divers or remotely operated vehicles are working below a vessel that cannot easily move out of the way.
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.
Until further notice
The operation or danger has no scheduled end; the warning stays in force until a later message cancels it.
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.
Wide berth requested
Keep well clear — or, when a distance is given ("TWO MILE BERTH REQUESTED"), at least that far away.

All warning terms →

Collected reports in this area · survey operations

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

03
05
10
15
20
24

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

Worldwide in the collected sources

55 survey operations listed in force · see all

Record snapshot 2026-10-02 05:48Z; source collection times vary.

Surveys

Hydrographic and scientific survey vessels, often towing long arrays. All current survey operations →

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.