Surveys

Survey operations 19 apr thru 28 may by M/V thalassa along trackline joining 47-50.31N 004-08.86W, 43-22.95N…

Bay of Biscay · HYDROLANT 824/24

What this record establishes

Archived notice · 2024-04-29 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) · AVURNAV BREST 111/24 171731Z APR 24.. Issued 2024-04-17 20:36Z. 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: Bay of Biscay. The map shows the reported line or operation extent; it is not a vessel track. Check the original wording for limits and qualifications.

Current notices and reporting history in the Bay of Biscay →

issued: 2024-04-17 20:36Z
status: Archived notice
self-cancels: 2024-04-29 00:01Z
authority: AVURNAV BREST 111/24 171731Z APR 24.
issued by: AVURNAV BREST
sea: Bay of Biscay
position: 45.611, -2.961
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

BAY OF BISCAY.
FRANCE.
DNC 08.
1. SURVEY OPERATIONS 19 APR THRU 28 MAY BY
   M/V THALASSA ALONG TRACKLINE JOINING
   47-50.31N 004-08.86W, 43-22.95N 001-46.49W.
   WIDE BERTH REQUESTED.
2. CANCEL THIS MSG 290001Z APR 24.

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.
Track line joining: Introduces a route through a series of positions — a cable route, a tow's track or a survey line.
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.
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.

All warning terms →

Collected reports in this area · survey operations

96 within 180 nm since 1999 · 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

55 survey operations listed in force · see all

Record snapshot 2026-09-30 11:30Z; 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.