In force
Currently valid: broadcast and not yet cancelled.
A navigational warning is in force from the moment it is broadcast until it is cancelled — by a later message, by its own cancellation time, or when a coordinator drops it from its list. Coordinators periodically broadcast the numbers of all warnings in force so that a ship joining an area can check it has them all.
On seahazards, "in force" means in force in the most recent list we collected from that source. Where we only hold the historical archive, the status reflects the archive's record, not an observation we made at the time.
What the archive shows
35 messages in this archive use “In force”, the earliest issued 1984-01-01 and the latest 2025-02-15. 1 of them is in force in the latest lists we collected. A hazard reported again and again counts once per message.
The largest yearly count is 2008, with 8 messages. Collection is incomplete between 2024-05 and 2026-08-17, so 2024 and 2025 are not comparable with fully collected years.
Other accounts for 25 of 35 recorded messages (71%), the largest warning type group in this selection.
By warning series: HYDROPAC 12, HYDROLANT 9, NAVAREA XII 6 and NAVAREA IV 6, and 2 more.
Messages using it, by year of issue
By month of issue, all years
In force now · 1
- NAVAREA IV 190/25 · Other2025-02-14 · in force
LABRADOR SEA. CANADA ICE CONTROL ZONE TANGO (T) HAS BEEN FULLY ACTIVATED AND DECLARED IN FORCE BY CANADIAN AUTHORITIES. ALL LADEN OIL TANKERS AND SHIPS CARRYING CHEMICALS IN BULK…
Canada ice control zone tango (t) has been fully activated and declared in force by canadian authorities →
How it reads in recent messages
- NAVAREA XII 220/23 · Other2023-04-18
…XII WARNINGS VIA IRIDIUM SAFETYCAST SERVICES. ALTERNATIVELY, THE COMPLETE TEXT OF ALL IN-FORCE NAVAREA XII BROADCAST WARNINGS MAY BE REQUESTED BY E-MAIL AT NAVSAFETY@NGA.MIL.
Inmarsat safetynet services in pacific ocean region (por) degraded until further notice → - NAVAREA XII 332/16 · Other2016-09-13
…GUARD MARINE SAFETY INFORMATION BULLETIN 01-16 (CHANGE 2) AT WWW.USCG.MIL/MSIB REMAINS IN FORCE FOR INFORMATION ON MARITIME INDUSTRY REPORTING REQUIREMENTS FOR VESSEL CREWMEMBERS OR…
Flag operators are requested to forward this advisory to their ships by the most expeditious means → - HYDROARC 236/16 · Other2016-09-13
…GUARD MARINE SAFETY INFORMATION BULLETIN 01-16 (CHANGE 2) AT WWW.USCG.MIL/MSIB REMAINS IN FORCE FOR INFORMATION ON MARITIME INDUSTRY REPORTING REQUIREMENTS FOR VESSEL CREWMEMBERS OR…
Flag operators are requested to forward this advisory to their ships by the most expeditious means → - NAVAREA IV 778/16 · Other2016-09-13
…GUARD MARINE SAFETY INFORMATION BULLETIN 01-16 (CHANGE 2) AT WWW.USCG.MIL/MSIB REMAINS IN FORCE FOR INFORMATION ON MARITIME INDUSTRY REPORTING REQUIREMENTS FOR VESSEL CREWMEMBERS OR…
Flag operators are requested to forward this advisory to their ships by the most expeditious means → - HYDROPAC 2237/15 · Other2015-07-06
…2169/15, 2176/15, 2198/15, 2213/15, 2217/15, 2235/15. 2. CANCEL HYDROPAC 1470/15, MSG IN FORCE AS MARAD ADVISORY 1/15 AND AVAILABLE AT MSI.NGA.MIL. 3. CANCEL THIS MSG.
Cancel HYDROPAC 1076/13, 1178/13, 2019/13, 2988/13, 3276/13, 3708/13, 656/14, 2360/14, 2942/14, 600/15,… → - HYDROLANT 1554/15 · Other2015-06-24
…1442/15, 1425/15, 1422/15, 1405/15, 1391/15, 1371/15. 2. CANCEL HYDROLANT 1062/15, MSG IN FORCE AS MARAD ADVISORY 1/15 AND AVAILABLE AT MSI.NGA.MIL. 3. CANCEL THIS MSG.
Cancel HYDROLANT 1533/15, 1531/15, 1530/15, 1522/15, 1515/15, 1513/15, 1508/15, 1501/15, 1469/15, 1464/15,… → - HYDROPAC 3872/14 · Other2014-12-28
1. CANCEL HYDROPAC 3395/14, MSG IN FORCE AS MARAD ADVISORY 3/14 AND AVAILABLE AT MSI.NGA.MIL. 2. CANCEL HYDROPAC 3777/14,…
Cancel HYDROPAC 3395/14, msg in force as marad advisory 3/14 and available at msi.nga.mil →
Earliest in the archive
- SPECIAL 0/83 · Other1983-12-31
…consecutively and further promulgated in the Notice to Mariners. SPECIAL WARNINGS in force ****: NOS. 1, 29, 71, 77, 81, 82, 89, 92, 95, 100, 102, 103, 104, 105, 107, 108, 109,110…
Special warnings, primarily intended to announce official government proclamations affecting shipping, are… →
Often in the same message
Related terms
- Cancellation reference
- A line that cancels an earlier warning by its number, such as CANCEL HYDROLANT 1085/12.
- CANCEL THIS MSG
- The warning's own expiry: a line telling the reader when the message cancels itself.
- Until further notice
- The operation or danger has no scheduled end; the warning stays in force until a later message cancels it.
- Maritime Safety Information (MSI)
- Navigational and meteorological warnings, forecasts and other urgent safety messages broadcast to ships.
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.