Surveys

Survey operations in progress until further notice by M/V alliance towing equipment along trackline joining…

Tyrrhenian Sea · HYDROLANT 1659/09

What this record establishes

Archived notice · 2009-10-17 09:32Z

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 343/09 311150Z AUG 09.. Issued 2009-08-31 15:14Z. 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
2009-08-31 15:14Z
status
Archived notice
authority
NAVAREA III 343/09 311150Z AUG 09.
NAVAREA
NAVAREA III · named as the source of this relay
sea
Tyrrhenian Sea
position
40.856, 10.707
vessel
M/V ALLIANCE · 61 messages
source
NGA MSI broadcast-warn JSON (archive, frozen 2024-05) · first seen 2026-08-17 13:38Z

Original warning text

1. SURVEY OPERATIONS IN PROGRESS UNTIL FURTHER
   NOTICE BY M/V ALLIANCE TOWING EQUIPMENT
   ALONG TRACKLINE JOINING
   39-39.8N 010-07.1E, 40-07.2N 010-11.4E,
   40-39.3N 010-13.6E, 40-54.5N 011-30.0E,
   41-10.7N 010-12.3E, 41-25.3N 011-24.8E.
   WIDE BERTH REQUESTED.
2. CANCEL HYDROLANT 1640/09.

Reading this warning

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.
Tow / towing
A vessel towing another vessel, a barge or a structure — slow, hard to manoeuvre, and with a long line between.
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.

All warning terms →

Collected reports in this area · survey operations

145 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

50 survey operations listed in force · see all

Record snapshot 2026-09-24 23:07Z; 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.