Surveys

Underwater operations 29 jul thru 11 aug by M/V yokosuka with submersible shinkai 6500 in areas bound by: a.…

North Pacific Ocean · HYDROPAC 2467/23

What this record establishes

Archived notice · 2023-08-12 00:01Z

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 XI 255/23 281837Z JUL 23.. Issued 2023-07-28 22:42Z. 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 Pacific 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 Pacific Ocean →

issued
2023-07-28 22:42Z
status
Archived notice
self-cancels
2023-08-12 00:01Z
authority
NAVAREA XI 255/23 281837Z JUL 23.
NAVAREA
NAVAREA XI · named as the source of this relay
sea
North Pacific Ocean
position
10.375, 142.250
vessel
M/V YOKOSUKA · 99 messages
source
NGA MSI broadcast-warn JSON (archive, frozen 2024-05) · first seen 2026-08-17 13:38Z

Original warning text

WESTERN NORTH PACIFIC.
MICRONESIA, FEDERATED STATES OF.
DNC 12.
1. UNDERWATER OPERATIONS 29 JUL THRU 11 AUG
   BY M/V YOKOSUKA WITH SUBMERSIBLE SHINKAI 6500
   IN AREAS BOUND BY:
A. 09-45.00N 141-30.00E, 11-00.00N 141-30.00E,
   11-00.00N 143-00.00E, 09-45.00N 143-00.00E.
B. 19-10.00N 146-30.00E, 19-40.00N 146-30.00E,
   19-40.00N 146-50.00E, 19-10.00N 146-50.00E.
2. CANCEL HYDROPAC 2463/23, 2464/23, 2465/23 AND 2466/23.
3. CANCEL THIS MSG 120001Z 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.
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.
Cancellation reference
A line that cancels an earlier warning by its number, such as CANCEL HYDROLANT 1085/12.
HYDROPAC
The U.S. long-range warning series for the Pacific outside NAVAREA XII and for the Indian Ocean, Persian Gulf and adjoining seas.
CANCEL THIS MSG
The warning's own expiry: a line telling the reader when the message cancels itself.
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.

All warning terms →

Collected reports in this area · survey operations

6 within 180 nm since 2002 · 0 in the last 12 months · 0 listed in force now

02
05
10
15
20
23

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

55 survey operations listed in force · see all

Record snapshot 2026-10-02 08:17Z; 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.