Other

Hydrographic operations 120001Z sep to 120001Z oct in area bound by 59-00N 166-30W, 55-00N 158-00W, 60-00N…

NAVAREA XII 312/99

What this record establishes

Archived notice · 1999-10-12 01:01Z

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) · CTF TWELVE 100301Z SEP 99. Issued 1999-09-10 03:50Z. 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
No named location parsed. The map shows an area described by the warning; the listed coordinate is its representative center. Check the original wording for limits and qualifications.

Activity windows · 1 in this warning

opens (UTC)closes (UTC)locallength
1999-09-12 00:01Z1999-10-12 00:01Z—720 h

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

issued
1999-09-10 03:50Z
status
Archived notice
self-cancels
1999-10-12 01:01Z
authority
CTF TWELVE 100301Z SEP 99
NAVAREA
NAVAREA XII
issued by
CTF TWELVE
position
51.514, -67.226
source
NGA MSI broadcast-warn JSON (archive, frozen 2024-05) · first seen 2026-08-17 13:38Z

Original warning text

1. HYDROGRAPHIC OPERATIONS 120001Z SEP TO 120001Z OCT
   IN AREA BOUND BY 59-00N 166-30W, 55-00N 158-00W,
   60-00N 145-00W, 55-00N 135-00W, 52-00N 135-00W,
   48-00N 147-00W, 48-00N 158-00W, 30-00N 165-00W,
   30-00N 180-00, 47-00N 174-00W, 50-00N 179-00W,
   53-00N 172-00E, 56-00N 177-00W.
2. CANCEL THIS MSG 120101Z OCT.

Reading this warning

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 · other warnings

4 within 180 nm since 1999 · 0 in the last 12 months · 0 listed in force now

99
00
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

21 other warnings listed in force · see all

Record snapshot 2026-10-02 20:21Z; source collection times vary.

Other

Everything the classifier did not place elsewhere. All current other warnings →

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.