Other

Underwater ordnance detonations 160001Z to 160430Z mar, alternate 170001Z to 170430Z mar in area bound by…

Gulf of Tonkin · Vietnam · HYDROPAC 887/17

issued
2017-03-15 06:17Z
status
cancelled 2017-03-17 05:30Z (archive)
self-cancels
2017-03-17 05:30Z
authority
HAIPHONG RADIO 150410Z MAR 17.
sea
South China Sea
position
20.775, 107.485
source
nga_json · first seen 2026-08-17 13:38Z

Original warning text

GULF OF TONKIN.
VIETNAM.
DNC 23.
1. UNDERWATER ORDNANCE DETONATIONS 160001Z TO 160430Z MAR,
   ALTERNATE 170001Z TO 170430Z MAR IN AREA BOUND BY
   20-49.1N 107-25.8E, 20-44.0N 107-25.8E,
   20-44.0N 107-32.8E, 20-49.1N 107-32.0E.
2. CANCEL THIS MSG 170530Z MAR 17.

Activity windows · 2 in this warning

opens (UTC)closes (UTC)locallength
2017-03-16 00:01Z2017-03-16 04:30Z4 h 29
2017-03-17 00:01Z2017-03-17 04:30Z4 h 29

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

This area · other warnings

27 within 180 nm since 2012 · 0 in the last 12 months · 0 in force now

12
15
20
24

Season · when other warnings 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

Nothing else in force within 120 nm.

Worldwide now

34 other warnings in force · see all

Other

Everything the classifier did not place elsewhere. All current other warnings

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.