Incidents · overdue

Submarine unreported

South Atlantic Ocean · HYDROLANT 3720/17

What this record establishes

Archived notice · 2017-11-24 21:47Z

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 VI 690/17 180254Z NOV 17.. Issued 2017-11-18 03:12Z. 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
South Atlantic Ocean. The map shows an area described by the warning; the listed coordinate is its representative center. Check the original wording for limits and qualifications.

Related notices and cancellation links

These reports were linked by category and sea, with positions within 30 nautical miles and issue dates within 30 days of another report's recorded in-force span. Links can extend through other members, so the full group can cover a larger area or period. Proximity does not confirm that they describe one incident.

  1. HYDROLANT 3720/17 · this notice2017-11-18 · Archived notice
  2. HYDROLANT 3780/172017-11-23 · Archived notice
  3. HYDROLANT 3801/172017-11-24 · Archived notice
  4. HYDROLANT 3865/172017-11-30 · Archived notice
  5. HYDROLANT 3879/172017-12-01 · Archived notice
  6. HYDROLANT 4129/172017-12-20 · Archived notice
Compare all 6 notices, changes and original texts →

Current notices and reporting history in the South Atlantic Ocean →

issued
2017-11-18 03:12Z
status
Archived notice
authority
NAVAREA VI 690/17 180254Z NOV 17.
NAVAREA
NAVAREA VI · named as the source of this relay
sea
South Atlantic Ocean
position
-44.877, -59.047
source
NGA MSI broadcast-warn JSON (archive, frozen 2024-05) · first seen 2026-08-17 13:38Z

Original warning text

WESTERN SOUTH ATLANTIC.
DNC 07.
SUBMARINE UNREPORTED. LAST KNOWN POSITION IN
46-44.4S 060-08.4W AT 150330Z NOV. SEARCH AND
RESCUE OPERATIONS IN AREA BOUND BY
44-20.0S 060-45.0W, 43-45.0S 057-50.0W,
45-20.0S 057-12.0W, 45-55.0S 060-07.0W.
VESSELS IN VICINITY REQUESTED TO KEEP A SHARP
LOOKOUT, ASSIST IF POSSIBLE.  REPORTS TO MRCC
PUERTO BELGRANO, INMARSAT-C: 470100125,
PHONE: 5429 3248 7150, 5429 3248 7162.

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.
Last known position
The most recent confirmed position of a missing vessel or person — the starting point of a search.
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.
Date-time group (DTG)
A compact UTC timestamp — day, hour and minute followed by Z — such as 201500Z for the 20th at 15:00 UTC.
Area bound by
Introduces a list of positions that are the corners of an area — the polygon the warning applies to.
Keep a sharp lookout
A request to every ship in the area to watch for the vessel, people or object described.
Assist if possible
The second half of the standard rescue request: ships able to help are asked to do so.
MRCC (Maritime Rescue Coordination Centre)
A rescue coordination centre for maritime cases only, such as MRCC Fort-de-France or MRCC Vietnam.
Inmarsat-C / SafetyNET
The satellite system that carries NAVAREA warnings to ships at sea, and the terminal number rescue centres give for reports.

All warning terms →

Collected reports in this area · distress & casualty cases (archived)

18 within 180 nm since 2005 · 0 in the last 12 months · 0 listed in force now

05
10
15
20
21

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

0 distress & casualty cases (archived) listed in force · see all

Record snapshot 2026-10-02 13:02Z; source collection times vary.

Incidents

Search-and-rescue broadcasts, published only once a case has been closed for 30 days: groundings, sinkings, capsizes, fires, man overboard, overdue vessels. Nothing here is live. All current distress & casualty cases (archived) →

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.