Discoloured water reported near 20-26.0N 145-01.0E on 16 July at 0013Z; cancels warning 0020/24.
North Pacific Ocean · NAVAREA XI 322/26
What this record establishes
Listed in force
The latest collected record lists this warning as active. This is the status of the notice, not a live observation of conditions at the location.
- Source and dates
- Japan Coast Guard JHOD NAVAREA XI · Japan Coast Guard (JHOD). Issued 2026-07-16 18:00Z. First collected 2026-08-17 13:42Z; last seen in collection 2026-08-17 14:24Z. Collection dates record ingestion, not a new incident or a fresh field observation.
- Location covered
- North Pacific Ocean. The parsed report position is 20.433, 145.017. 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.
- HYDROPAC 12/242024-01-01 · Cancelled notice
- HYDROPAC 153/242024-01-13 · Cancelled notice
- NAVAREA XI 322/26 · this notice2026-07-16 · Listed in force
- HYDROPAC 2039/262026-07-16 · Listed in force
Current notices and reporting history in the North Pacific Ocean →
- issued
- 2026-07-16 18:00Z
- status
- Listed in force
- authority
- Japan Coast Guard (JHOD)
- NAVAREA
- NAVAREA XI
- issued by
- JAPAN COAST GUARD
- sea
- North Pacific Ocean
- position
- 20.433, 145.017
- nearest port
- Saipan · 315 nm
- source
- Japan Coast Guard JHOD NAVAREA XI · first seen 2026-08-17 13:42Z
Original warning text
NORTH PACIFIC, MARIANAS. DISCOLOURED WATER REPORTED IN VICINITY OF 20-26.0N 145-01.0E AT 160013Z JUL. CANCEL 0020/24.
Reading this warning
- 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.
Nearest volcano
Ahyi · 1 km
Conditions at the position · now
loading…
MET Norway · NOAA WaveWatch III · HYCOM · GEBCO 2020 · model data at the centroid, not an observation
Collected reports in this area · volcanic activity
10 within 180 nm since 1999 · 2 in the last 12 months · 2 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.
- Discolored water with increased likelihood of submarine volcanic activity reported in vicinity 20-26.00N…2026-07-16
- Discolored water with increased likelihood of submarine volcanic activity reported in 20-25.00N 145-01.00E…2024-01-13
- Discolored water with submarine volcanic activity reported in 20-25.2N 145-01.8E at 012230Z jan2024-01-01
- Discolored water with submarine volcanic activity reported in 20-25.20N 145-01.80E at 270127Z jan2023-01-28
- Cancel HYDROPAC 1304/142014-05-06
- Mariana Islands2014-05-05
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
Worldwide in the collected sources
12 volcanic activity listed in force · see all
Record snapshot 2026-09-25 07:30Z; 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.