Surveys

Underwater operations are underway off Brazil in the South Atlantic daily from 11 to 25 September, 1100 to 2100, near 20-23.78S 040-09.43W; wide berth requested.

South Atlantic · Brazil · HYDROLANT 1794/26

issued
2026-09-10 09:39Z
status
cancelled 2026-09-10 13:50Z (dropped from inforce)
self-cancels
2026-09-25 22:00Z
sea
South Atlantic Ocean
position
-20.396, -40.157
source
nga_inforce · first seen 2026-09-10 14:17Z

Original warning text

SOUTH ATLANTIC.
BRAZIL.
1. UNDERWATER OPERATIONS 1100Z TO 2100Z
   DAILY 11 THRU 25 SEP BY M/V COMANDO B
   AND M/V SOMNIUM AUSTRALIS IN
   20-23.78S 040-09.43W.
   WIDE BERTH REQUESTED.
2. CANCEL THIS MSG 252200Z SEP 26.

Activity windows · 15 in this warning

opens (UTC)closes (UTC)locallength
2026-09-11 11:00Z2026-09-11 21:00Z—10 h
2026-09-12 11:00Z2026-09-12 21:00Z—10 h
2026-09-13 11:00Z2026-09-13 21:00Z—10 h
2026-09-14 11:00Z2026-09-14 21:00Z—10 h
2026-09-15 11:00Z2026-09-15 21:00Z—10 h
2026-09-16 11:00Z2026-09-16 21:00Z—10 h
2026-09-17 11:00Z2026-09-17 21:00Z—10 h
2026-09-18 11:00Z2026-09-18 21:00Z—10 h
… 7 more

Parsed from the warning text; outside these windows the area is normally not active, but the warning stays in force until cancelled.

This area · survey operations

576 within 180 nm since 2000 · 37 in the last 12 months · 2 in force now

00
05
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20
25
26

Season · when survey operations happen here

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F
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A
M
J
J
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S
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month of issue, all years in the archive

Nearby now · within 120 nm

Worldwide now

58 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.