Surveys

Underwater operations in progress sunrise to sunset until 191800Z nov by M/V thalassa within 20 miles of: a.…

HYDROLANT 2473/99

issued
1999-11-18 09:55Z
status
cancelled 1999-11-19 14:19Z (archive)
self-cancels
1999-11-19 19:00Z
cancels
HYDROLANT 2393/99HYDROLANT 2463/99
authority
WZ 2059/99 180916Z NOV 99; WZ 2958/99
sea
Celtic Sea
position
50.750, -9.500
source
nga_json · first seen 2026-08-17 13:38Z

Original warning text

1. UNDERWATER OPERATIONS IN PROGRESS SUNRISE TO SUNSET
   UNTIL 191800Z NOV BY M/V THALASSA WITHIN 20 MILES OF:
   A. 51-00N 010-00W ON 18 NOV.
   B. 50-30N 009-00W ON 19 NOV.
2. CANCEL HYDROLANT 2393/99(37), OPERATIONS COMPLETED.
3. CANCEL HYDROLANT 2463/99.
4. CANCEL THIS MSG 191900Z NOV.

This area · survey operations

450 within 180 nm since 1999 · 0 in the last 12 months · 0 in force now

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Season · when survey operations happen here

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month of issue, all years in the archive

Timeline

Nearby now · within 120 nm

Nothing else in force within 120 nm.

Worldwide now

84 survey operations in force · see all

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.