Surveys

Underwater operations 16 thru 31 may along trackline joining 43-24.77N 007-54.03E, 43-27.27N 007-57.26E,…

Tyrrhenian Sea · HYDROLANT 1654/20

What this record establishes

Archived notice · 2020-06-01 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) · NAVAREA III 742/20 151103Z MAY 20.. Issued 2020-05-15 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
Tyrrhenian Sea. 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 Tyrrhenian Sea →

issued
2020-05-15 13:54Z
status
Archived notice
authority
NAVAREA III 742/20 151103Z MAY 20.
NAVAREA
NAVAREA III · named as the source of this relay
sea
Tyrrhenian Sea
position
42.071, 10.649
source
NGA MSI broadcast-warn JSON (archive, frozen 2024-05) · first seen 2026-08-17 13:38Z

Original warning text

LIGURIAN SEA.
TYRRHENIAN SEA.
CORSICA.
DNC 08, DNC 09.
1. UNDERWATER OPERATIONS 16 THRU 31 MAY
   ALONG TRACKLINE JOINING
   43-24.77N 007-54.03E, 43-27.27N 007-57.26E,
   43-50.70N 009-06.48E, 43-50.06N 009-07.36E,
   43-50.10N 009-07.08E, 43-07.98N 009-40.48E,
   42-57.18N 009-42.92E, 42-31.36N 009-54.76E,
   42-15.69N 010-15.65E, 40-15.29N 012-55.16E,
   39-55.40N 013-27.40E.
2. CANCEL THIS MSG 01 JUN 20.

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.
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.
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

200 within 180 nm since 1998 · 0 in the last 12 months · 0 listed in force now

98
00
05
10
15
20
24

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

J
F
M
A
M
J
J
A
S
O
N
D

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 2026-10-01 12:56Z; 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.