Underwater operations in progress until further notice by M/V atlantic guardian along trackline between…
Bristol Channel · HYDROLANT 970/15
What this record establishes
Archived notice · 2015-04-25 19:18Z
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 501/15 221313Z APR 15.. Issued 2015-04-22 13:54Z. 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
- Bristol Channel. 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
- Celtic sea DNC 20cancelled by this notice
- Underwater operations in progress until further notice by M/V atlantic guardian vicinity of trackline…later cancellation notice
Current notices and reporting history in the Bristol Channel →
- issued
- 2015-04-22 13:54Z
- status
- Archived notice
- authority
- WZ 501/15 221313Z APR 15.
- issued by
- WZ
- sea
- Bristol Channel
- position
- 51.295, -4.678
- vessel
- M/V ATLANTIC GUARDIAN · 39 messages
- source
- NGA MSI broadcast-warn JSON (archive, frozen 2024-05) · first seen 2026-08-17 13:38Z
Original warning text
BRISTOL CHANNEL. DNC 20. 1. UNDERWATER OPERATIONS IN PROGRESS UNTIL FURTHER NOTICE BY M/V ATLANTIC GUARDIAN ALONG TRACKLINE BETWEEN 51-17.7N 004-55.3W AND 51-17.7N 004-26.1W. WIDE BERTH REQUESTED. 2. CANCEL HYDROLANT 961/15.
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.
- Underwater operations
- Divers or remotely operated vehicles are working below a vessel that cannot easily move out of the way.
- 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.
- 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
770 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 further notice by M/V sw amundsen towing seven 2200 meter long cables in…2024-04-18
- Survey operations in progress until further notice by M/V mintaka I in vicinity of trackline joining…2023-08-06
- 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
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 05:34Z; 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.