Survey operations 20 thru 25 apr by M/V oceanic sirius towing 12 11112 meter cables in area bound by…
South Atlantic Ocean · HYDROLANT 1094/21
What this record establishes
Archived notice · 2021-04-23 21:39Z
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 V 174/21 202043Z APR 21.. Issued 2021-04-20 21:00Z. 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 map shows an area described by the warning; the listed coordinate is its representative center. Check the original wording for limits and qualifications.
Related notices and cancellation links
Current notices and reporting history in the South Atlantic Ocean →
- issued
- 2021-04-20 21:00Z
- status
- Archived notice
- authority
- NAVAREA V 174/21 202043Z APR 21.
- NAVAREA
- NAVAREA V · named as the source of this relay
- sea
- South Atlantic Ocean
- position
- -22.007, -36.722
- vessel
- M/V OCEANIC SIRIUS · 102 messages
- source
- NGA MSI broadcast-warn JSON (archive, frozen 2024-05) · first seen 2026-08-17 13:38Z
Original warning text
WESTERN SOUTH ATLANTIC. BRAZIL-EAST COAST. DNC 01. 1. SURVEY OPERATIONS 20 THRU 25 APR BY M/V OCEANIC SIRIUS TOWING 12 11112 METER CABLES IN AREA BOUND BY 24-06.05S 040-01.32W, 21-36.20S 040-02.03W, 19-45.23S 037-32.23W, 19-38.48S 033-53.58W, 23-52.40S 033-44.53W, 24-06.65S 040-01.32W. WIDE BERTH REQUESTED. 2. CANCEL THIS MSG 26 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.
- 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.
Collected reports in this area · survey operations
148 within 180 nm since 2000 · 2 in the last 12 months · 1 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.
- Survey operations in progress until 10 nov 27 by M/V rem saltire in area bound by 21-39.40S 039-49.11W,…2026-09-11
- Underwater operations in progress until 140001Z nov by M/V fugro vaquita in area bound by 22-03.00S…2026-06-17
- Survey operations in progress until 02 jul by M/V atlantic guardian in area bound by 20-20.58S 038-21.07W,…2024-05-03
- Survey operations 10 thru 17 jan by M/V ramform tethys towing 12 6000 meter long cables in area bound by…2023-01-09
- Survey operations 09 thru 16 jan by M/V pgs apollo towing six 400 meter long cables in area bound by…2023-01-08
- Survey operations 02 thru 09 jan by M/V pgs apollo irin towing six 400 meter long cables in area bound by…2023-01-01
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 06:20Z; 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.