Operations at sea

Submarine operations

Submarines may be exercising submerged in the area; ships are asked to keep a lookout and avoid it.

Some navies broadcast the areas where their submarines exercise, asking surface ships to keep clear or to navigate with caution. A submerged submarine may be unable to see or hear a small vessel near the surface.

Note that "submarine" in other warnings often means "undersea" — a submarine cable or a submarine volcano. This term only matches warnings about the vessels.

What the archive shows

3 messages in this archive use “Submarine operations”, the earliest issued 1999-04-18 and the latest 2004-06-20. None of them is in force in the latest lists we collected. A hazard reported again and again counts once per message.

3 recorded messages form a small sample; the warning type breakdown should be read as individual records rather than a pattern.

Every located message that uses it lies in Mediterranean Sea - Western Basin.

By warning series: HYDROLANT 3.

Messages using it, by year of issue

'99
'00
'01
'02
'03
'04

Where it appears · 1 sea areas

How it reads in recent messages

  1. HYDROLANT 1042/04 · Cable ops2004-06-19

    1. SUBMARINE OPERATIONS 22 JUN UNTIL FURTHER NOTICE BY CABLESHIP PERTINACIA WITH SUBMERSIBLE IN AREAS BETWEEN:…

    Submarine operations 22 jun until further notice by cableship pertinacia with submersible in areas between:…
  2. HYDROLANT 1064/99 · Exercises · Mediterranean Sea - Western Basin1999-05-24

    1. SUBMARINE OPERATIONS 0800Z TO 1400Z DAILY 25 THRU 28 MAY BY M/V ANTEDON IN AREA BOUND BY 42-56N 006-00E,…

    Submarine operations 0800Z to 1400Z daily 25 thru 28 may by M/V antedon in area bound by 42-56N 006-00E,…
  3. HYDROLANT 760/99 · Exercises1999-04-17

    1. SUBMARINE OPERATIONS 181800Z THRU 231600Z APR IN AREA BETWEEN 38-30N 40-00N AND 009-30E 011-00E. 2. CANCEL…

    Submarine operations 181800Z thru 231600Z apr in area between 38-30N 40-00N and 009-30E 011-00E

Often in the same message

Related terms

Naval exercise
Warships, submarines or aircraft exercising in an area, sometimes with firings, sometimes simply to keep traffic clear.
Towed array / streamer
Equipment towed a long way behind a vessel — sonar, a hydrophone cable, a sampling sled — invisible at the surface.

Warning types that use it

Counts cover the messages in this archive that use the term, recounted 2026-09-24; see coverage for what is collected and since when. Not for navigation — follow official NAVAREA and coastal broadcasts.

Submarine operations — what it means in a navigational warning · seahazards