Surveys

Underwater operations 171400Z T0 191400Z aug in area bound by 46-17.50N 142-33.80E, 46-23.00N 142-51.00E,…

Sea of Okhotsk · HYDROPAC 2604/23

What this record establishes

Archived notice · 2023-08-19 15:00Z

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 XIII 100/23 120915Z AUG 23.. Issued 2023-08-12 09:20Z. 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: Sea of Okhotsk. 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 Sea of Okhotsk →

issued: 2023-08-12 09:20Z
status: Archived notice
self-cancels: 2023-08-19 15:00Z
authority: NAVAREA XIII 100/23 120915Z AUG 23.
NAVAREA: NAVAREA XIII · named as the source of this relay
sea: Sea of Okhotsk
position: 46.125, 142.817
source: NGA MSI broadcast-warn JSON (archive, frozen 2024-05) · first seen 2026-08-17 13:38Z

Original warning text

SEA OF OKHOTSK.
JAPAN.
DNC 24.
1. UNDERWATER OPERATIONS 171400Z T0 191400Z AUG
   IN AREA BOUND BY
   46-17.50N 142-33.80E, 46-23.00N 142-51.00E,
   46-19.50N 143-02.00E, 45-55.00N 143-06.30E,
   45-55.00N 142-33.08E.
   WIDE BERTH REQUESTED.
2. CANCEL THIS MSG 191500Z 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.
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.
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.
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 · survey operations

12 within 180 nm since 2005 · 1 in the last 12 months · 1 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

56 survey operations listed in force · see all

Record snapshot 2026-10-01 14:14Z; 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.