Underwater operations 09 thru 31 mar by M/V thalassa in: a. 00-00S 010-00W
South Atlantic Ocean · HYDROLANT 647/21
What this record establishes
Archived notice · 2021-04-01 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 II 100/21 051413Z MAR 21.. Issued 2021-03-05 14:23Z. 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 Atlantic Ocean. The parsed report position is -2.000, -6.667. It is a position in the source message, not a live location. Check the original wording for limits and qualifications.
Current notices and reporting history in the South Atlantic Ocean →
- issued
- 2021-03-05 14:23Z
- status
- Archived notice
- authority
- NAVAREA II 100/21 051413Z MAR 21.
- NAVAREA
- NAVAREA II · named as the source of this relay
- sea
- South Atlantic Ocean
- position
- -2.000, -6.667
- vessel
- M/V THALASSA · 139 messages
- source
- NGA MSI broadcast-warn JSON (archive, frozen 2024-05) · first seen 2026-08-17 13:38Z
Original warning text
SOUTH ATLANTIC. DNC 01. 1. UNDERWATER OPERATIONS 09 THRU 31 MAR BY M/V THALASSA IN: A. 00-00S 010-00W. B. 00-00S 000-00W. C. 06-00S 010-00W. WIDE BERTH REQUESTED. 2. CANCEL THIS MSG 01 APR 21.
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.
- 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.
Collected reports in this area · survey operations
6 within 180 nm since 2006 · 0 in the last 12 months · 0 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.
- Underwater operations 25 feb thru 07 apr by M/V thalassa in area bound by 00-00S 010-00W, 06-00S 010-00W,…2022-02-21
- Underwater operations 16 feb thru 23 mar by M/V thalassa in area bound by 00-00S 010-00W, 00-00S 000-00W,…2020-02-12
- Oceanographic operations 04 thru 18 apr by M/V le suroit along trackline joining 01-30N 010-00W, 00-00N…2012-04-02
- Oceanographic operations 26 mar thru 01 apr by M/V le suroit along trackline between 00-00N 010-00W and…2012-03-24
- Underwater operations 24 may to 16 jun by M/V atalante in area bound by 00-00 000-00, 10-00S 010-00W, 06-00S…2006-05-23
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
No other collected notice is currently listed in force within this radius. This does not establish safe conditions.
Worldwide in the collected sources
56 survey operations listed in force · see all
Record snapshot 2026-10-03 00:41Z; 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.