Surveys

Underwater operations occur daily 0800 to 1700 UTC from 17 September to 1 October in the South Atlantic off Brazil at 20-23.85S 040-09.08W, and vessels should keep clear.

South Atlantic · Brazil · HYDROLANT 1843/26

issued
2026-09-17 01:30Z
status
cancelled 2026-09-17 14:30Z (dropped from inforce)
self-cancels
2026-10-01 18:00Z
sea
South Atlantic Ocean
position
-20.398, -40.151
source
nga_inforce · first seen 2026-09-18 06:18Z

Original warning text

SOUTH ATLANTIC.
BRAZIL.
1. UNDERWATER OPERATIONS 0800Z TO 1700Z
   DAILY 17 SEP THRU 01 OCT BY M/V TOP WEATHER
   AND M/V COMANDO B IN 20-23.85S 040-09.08W.
   WIDE BERTH REQUESTED.
2. CANCEL THIS MSG 011800Z OCT 26.

Activity windows · 15 in this warning

opens (UTC)closes (UTC)locallength
2026-09-17 08:00Z2026-09-17 17:00Z9 h
2026-09-18 08:00Z2026-09-18 17:00Z9 h
2026-09-19 08:00Z2026-09-19 17:00Z9 h
2026-09-20 08:00Z2026-09-20 17:00Z9 h
2026-09-21 08:00Z2026-09-21 17:00Z9 h
2026-09-22 08:00Z2026-09-22 17:00Z9 h
2026-09-23 08:00Z2026-09-23 17:00Z9 h
2026-09-24 08:00Z2026-09-24 17:00Z9 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

586 within 180 nm since 2000 · 47 in the last 12 months · 2 in force now

00
05
10
15
20
25
26

Season · when survey operations happen here

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

month of issue, all years in the archive

Nearby now · within 120 nm

Worldwide now

52 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.