Volcanic

Discolored water in vicinity 27-13.6N 140-55.3E at 120643Z oct

Philippine Sea · HYDROPAC 2908/21

What this record establishes

Archived notice · 2022-03-25 12:51Z

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 325/21 121112Z OCT 21.. Issued 2021-10-12 12:57Z. 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
Philippine Sea. The parsed report position is 27.227, 140.922. It is a position in the source message, not a live location. Check the original wording for limits and qualifications.

Related notices and cancellation links

These reports were linked by category and sea, with positions within 30 nautical miles and issue dates within 30 days of another report's recorded in-force span. Links can extend through other members, so the full group can cover a larger area or period. Proximity does not confirm that they describe one incident.

  1. HYDROPAC 3739/202020-12-18 · Archived notice
  2. NAVAREA XI 488/202020-12-18 · Cancelled notice
  3. NAVAREA XI 325/212021-10-12 · Listed in force
  4. HYDROPAC 2908/21 · this notice2021-10-12 · Archived notice
  5. HYDROPAC 2909/212021-10-12 · Archived notice
  6. NAVAREA XI 326/212021-10-13 · Listed in force
Compare all 9 notices, changes and original texts →

Current notices and reporting history in the Philippine Sea →

issued
2021-10-12 12:57Z
status
Archived notice
authority
NAVAREA XI 325/21 121112Z OCT 21.
NAVAREA
NAVAREA XI · named as the source of this relay
sea
Philippine Sea
position
27.227, 140.922
source
NGA MSI broadcast-warn JSON (archive, frozen 2024-05) · first seen 2026-08-17 13:38Z

Original warning text

PHILIPPINE SEA.
JAPAN.
DNC 12.
DISCOLORED WATER IN VICINITY 27-13.6N 140-55.3E
AT 120643Z OCT.

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.
Discoloured water
Patches of unusually coloured sea — often a sign of a submarine volcano or of a shoal.
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.
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 · volcanic activity

87 within 180 nm since 1996 · 2 in the last 12 months · 7 listed in force now

96
00
05
10
15
20
25
26

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

12 volcanic activity listed in force · see all

Record snapshot 2026-10-01 16:40Z; source collection times vary.

Volcanic

Submarine eruptions, discoloured water, pumice rafts. All current volcanic activity →

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.