Surveys

Survey operations in progress until 10 oct by M/V polarcus alima towing six four mile long cables in area…

South China Sea · HYDROPAC 2624/20

What this record establishes

Archived notice · 2020-10-11 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 336/20 090132Z SEP 20.. Issued 2020-09-09 01:38Z. 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
South China Sea. 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 South China Sea →

issued
2020-09-09 01:38Z
status
Archived notice
authority
NAVAREA XI 336/20 090132Z SEP 20.
NAVAREA
NAVAREA XI · named as the source of this relay
sea
South China Sea
position
10.211, 108.354
vessel
M/V POLARCUS ALIMA · 115 messages
source
NGA MSI broadcast-warn JSON (archive, frozen 2024-05) · first seen 2026-08-17 13:38Z

Original warning text

SOUTH CHINA SEA.
DNC 11.
1. SURVEY OPERATIONS IN PROGRESS UNTIL 10 OCT BY
   M/V POLARCUS ALIMA TOWING SIX FOUR MILE
   LONG CABLES IN AREA BOUND BY
   09-58.8N 108-11.7E, 10-06.9N 108-05.0E,
   10-26.6N 108-31.0E, 10-18.5N 108-37.4E.
   WIDE BERTH REQUESTED.
2. CANCEL THIS MSG 11 OCT 20.

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.
Survey operations
A research or survey vessel is mapping the seabed or water column, often while towing equipment.
Towed array / streamer
Equipment towed a long way behind a vessel — sonar, a hydrophone cable, a sampling sled — invisible at the surface.
Tow / towing
A vessel towing another vessel, a barge or a structure — slow, hard to manoeuvre, and with a long line between.
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

25 within 180 nm since 2013 · 0 in the last 12 months · 0 listed in force now

13
15
20

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

50 survey operations listed in force · see all

Record snapshot 2026-09-24 23:58Z; 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.