Survey operations 30 mar until further notice by M/V ramform vanguard towing ten 8000 meter long cables in…
South Atlantic Ocean · HYDROLANT 677/23
What this record establishes
Archived notice · 2023-04-24 14:52Z
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 VII 95/23 281359Z MAR 23.. Issued 2023-03-28 14:21Z. 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
- Survey operations in progress until further notice by M/V ramform vanguard towing 14 4500 meter long cables…cancelled by this notice
- Cancel HYDROLANT 677/23 and this msglater cancellation notice
Current notices and reporting history in the South Atlantic Ocean →
- issued
- 2023-03-28 14:21Z
- status
- Archived notice
- authority
- NAVAREA VII 95/23 281359Z MAR 23.
- NAVAREA
- NAVAREA VII · named as the source of this relay
- sea
- South Atlantic Ocean
- position
- -7.306, 11.287
- vessel
- M/V RAMFORM VANGUARD · 519 messages
- source
- NGA MSI broadcast-warn JSON (archive, frozen 2024-05) · first seen 2026-08-17 13:38Z
Original warning text
EASTERN SOUTH ATLANTIC. ANGOLA. DNC 01. 1. SURVEY OPERATIONS 30 MAR UNTIL FURTHER NOTICE BY M/V RAMFORM VANGUARD TOWING TEN 8000 METER LONG CABLES IN AREA BOUND BY 07-18.10S 011-21.61E, 07-14.38S 011-18.61E, 07-18.00S 011-12.93E, 07-22.71S 011-15.93E. SEVEN MILE BERTH REQUESTED. 2. CANCEL HYDROLANT 458/23.
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.
- Until further notice
- The operation or danger has no scheduled end; the warning stays in force until a later message cancels it.
- 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.
- Cancellation reference
- A line that cancels an earlier warning by its number, such as CANCEL HYDROLANT 1085/12.
- HYDROLANT
- The U.S. long-range warning series for Atlantic waters outside NAVAREA IV, including the eastern Atlantic, the Mediterranean and adjoining seas.
Collected reports in this area · survey operations
74 within 180 nm since 2003 · 2 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.
- Survey operations in progress until further notice by M/V ramform victory towing 12 three mile long cables…2026-08-24
- Survey operations in progress until further notice by M/V ramform victory towing 12 three mile long cables…2026-07-03
- Survey operations in progress until further notice by M/V ramform tethys towing ten two mile long cables in…2024-09-17
- Survey operations in progress until further notice by M/V sw empress towing 7000 meter long cables in area…2023-08-12
- Survey operations in progress until further notice by M/V ramform vanguard towing 14 4500 meter long cables…2023-02-27
- Survey operations in progress until further notice by M/V ramform vanguard towing 12 6500 meter long cables…2023-01-05
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
- NAVAREA VII 246 of 2026 (24 aug 26) 1. south atlantic ocean - ne sector - offshore orange river mouth 2.…Cable ops · 59.1 nm
- Operation on cableOther · 106 nm
Worldwide in the collected sources
56 survey operations listed in force · see all
Record snapshot 2026-10-02 01:34Z; 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.