Surveys

Survey operations in progress until 250259Z aug by M/V ridley thomas in area bound by 03-43.63S 038-15.43W,…

South Atlantic Ocean · HYDROLANT 1353/15

What this record establishes

Archived notice · 2015-08-25 03:59Z

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 174/15 032308Z JUN 15.. Issued 2015-06-04 00:53Z. 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.

Current notices and reporting history in the South Atlantic Ocean →

issued: 2015-06-04 00:53Z
status: Archived notice
self-cancels: 2015-08-25 03:59Z
authority: NAVAREA V 174/15 032308Z JUN 15.
NAVAREA: NAVAREA V · named as the source of this relay
sea: South Atlantic Ocean
position: -15.285, -38.372
vessel: M/V RIDLEY THOMAS · 28 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.
DNC 01.
1. SURVEY OPERATIONS IN PROGRESS UNTIL 250259Z AUG
   BY M/V RIDLEY THOMAS IN AREA BOUND BY
   03-43.63S 038-15.43W, 03-27.57S 037-11.03W,
   03-10.17S 036-26.68W, 03-15.83S 034-58.06W,
   04-45.26S 033-22.06W, 10-04.92S 032-00.81W,
   23-19.62S 035-19.18W, 25-58.81S 043-58.79W,
   24-10.92S 046-27.79W.
   WIDE BERTH REQUESTED.
2. CANCEL THIS MSG 250359Z AUG 15.

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.
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.
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

12 within 180 nm since 2001 · 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.

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 04:22Z; 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.