Survey operations in progress until further notice by M/V ridley thomas along trackline joining 50-49N…
Celtic Sea · HYDROLANT 2521/20
What this record establishes
Archived notice · 2020-08-18 14:53Z
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) · WZ 858/20 141636Z AUG 20.. Issued 2020-08-14 16:41Z. 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
- Celtic Sea. The map shows the reported line or operation extent; it is not a vessel track. Check the original wording for limits and qualifications.
Related notices and cancellation links
- Cancel HYDROLANT 2521/20 and this msg, operations completedlater cancellation notice
- issued
- 2020-08-14 16:41Z
- status
- Archived notice
- authority
- WZ 858/20 141636Z AUG 20.
- issued by
- WZ
- sea
- Celtic Sea
- position
- 50.825, -5.500
- 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
CELTIC SEA. BRISTOL CHANNEL. ENGLAND. DNC 19, DNC 20. SURVEY OPERATIONS IN PROGRESS UNTIL FURTHER NOTICE BY M/V RIDLEY THOMAS ALONG TRACKLINE JOINING 50-49N 006-26W, 50-50N 004-34W. ONE MILE BERTH REQUESTED.
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.
- 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.
Collected reports in this area · survey operations
736 within 180 nm since 1999 · 1 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 in progress until further notice by M/V zwerver I in area bound by 53-34.50N…2026-09-14
- Survey operations in progress until 31 oct by M/V ramform vanguard towing cables in area bound by 53-44.12N…2024-09-26
- Survey operations in progress until 20 jul by M/V celtic explorer in vicinity of trackline joining 47-30.00N…2023-06-14
- Underwater operations 180800Z to 192200Z nov by M/V willchallenge in vicinity of 50-19.0N 004-14.7W2022-11-17
- Survey operations 15 sept thru 20 oct by M/V thlassa in vicinity of trackline joining 48-30.00N 006-00.00W,…2022-09-14
- Survey operations in progress until 10 sep by M/V laperouse and M/V borda along trackline joining 48-27.48N…2022-09-01
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
55 survey operations listed in force · see all
Record snapshot 2026-10-02 05:11Z; 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.