Navigation prohibited
Ships may not enter or pass through the area, or a port is closed to traffic.
The strongest instruction a warning carries. It closes a channel for an operation, a port for a storm or an incident, or an area for military activity. Port closures for tropical cyclones make up a noticeable part of these messages in the storm season.
Closures end with a later warning or at the stated time. The archive can tell you how long a closure was announced for, not how long ships actually waited.
What the archive shows
620 messages in this archive use “Navigation prohibited”, the earliest issued 1991-09-06 and the latest 2026-08-24. 4 of them are in force in the latest lists we collected. A hazard reported again and again counts once per message.
The largest yearly count is 2016, with 79 messages. Collection is incomplete between 2024-05 and 2026-08-17, so 2024, 2025 and 2026 are not comparable with fully collected years.
Restricted accounts for 538 of 620 recorded messages (87%), the largest warning type group in this selection.
Located messages that use it fall in 42 sea areas; the most frequent are North Atlantic Ocean (74), South Atlantic Ocean (73) and North Sea (58).
Messages that use it are issued most often in July (67 across all years) and least often in November (24).
By warning series: HYDROLANT 416, HYDROPAC 142, NAVAREA IV 33 and HYDROARC 22, and 3 more.
Messages using it, by year of issue
By month of issue, all years
Where it appears · 42 sea areas
In force now · 4
- HYDROPAC 1415/25 · Restricted · Persian Gulf2025-06-01 · in force
PERSIAN GULF. KUWAIT. DNC 10. NAVIGATION PROHIBITED UNTIL FURTHER NOTICE IN AREA WITHIN 600 METERS OF 29-13.10N 048-44.42E.
Navigation prohibited until further notice in area within 600 meters of 29-13.10N 048-44.42E → - HYDROPAC 28/25 · Restricted · Persian Gulf2025-01-06 · in force
PERSIAN GULF. KUWAIT. DNC 10. NAVIGATION PROHIBITED UNTIL FURTHER NOTICE IN AREA WITHIN 600 METERS OF 28-52.49N 048-21.63E.
Navigation prohibited until further notice in area within 600 meters of 28-52.49N 048-21.63E → - NAVAREA IV 1524/24 · Spills · Caribbean Sea2024-12-04 · in force
…SEA AREA (PSSA). 2. TO AVOID THE RISK OF POLLUTION AND DAMAGE TO THE ENVIRONMENT, ENTRY IS PROHIBITED FOR VESSELS OF 300 GROSS TONS AND GREATER, AND ANCHORING IS PROHIBITED FOR ALL VESSELS,…
Kitts and nevis → - NAVAREA III 92/22 · Mines · Black Sea2022-02-25 · in force
BLACK SEA NORTHWESTERN PART. 1.- DUE TO MINE DANGER NAVIGATION PROHIBITED UNTILL FURTHER NOTICE IN AREA BOUNDED BY: A 46-04.0N 033-12.8E 46-03.1N 033-13.9E…
Due to mine danger navigation prohibited untill further notice in area bounded by: a 46-04.0N 033-12.8E… →
How it reads in recent messages
- HYDROLANT 1658/26 · Restricted · South Atlantic Ocean2026-08-24
SOUTH ATLANTIC. BRAZIL. 1. NAVIGATION PROHIBITED 251100Z TO 251900Z AUG IN AREA WITHIN TWO MILES OF 26-53.00S 048-35.15W. WIDE BERTH…
Navigation prohibited 251100Z to 251900Z aug in area within two miles of 26-53.00S 048-35.15W → - HYDROPAC 2893/25 · Restricted · Persian Gulf2025-11-10
PERSIAN GULF. U.A.E. DNC 10. 1. NAVIGATION PROHIBITED UNTIL FURTHER NOTICE IN AREA BOUND BY 25-43.05N 055-45.82E, 25-42.87N 055-46.38E,…
Navigation prohibited until further notice in area bound by 25-43.05N 055-45.82E, 25-42.87N 055-46.38E,… → - HYDROPAC 942/25 · Restricted · Persian Gulf2025-04-11
PERSIAN GULF. U.A.E. DNC 10. NAVIGATION PROHIBITED UNTIL FURTHER NOTICE IN AREA BOUND BY 25-43.05N 055-45.82E, 25-42.87N 055-46.38E,…
Navigation prohibited until further notice in area bound by 25-43.05N 055-45.82E, 25-42.87N 055-46.38E,… → - HYDROPAC 1390/24 · Restricted · Sea of Okhotsk2024-04-27
SEA OF OKHOTSK. WESTERN NORTH PACIFIC. KURIL ISLANDS. DNC 24. 1. NAVIGATION PROHIBITED 271200Z APR TO 151200Z MAY IN AREA BOUND BY 47-48.40N 152-41.20E, 45-34.97N 147-42.51E,…
Navigation prohibited 271200Z apr to 151200Z may in area bound by 47-48.40N 152-41.20E, 45-34.97N… → - HYDROPAC 1379/24 · Restricted · Sea of Okhotsk2024-04-26
SEA OF OKHOTSK. WESTERN NORTH PACIFIC. KURIL ISLANDS. DNC 24. 1. NAVIGATION PROHIBITED UNTIL 151200Z MAY IN AREAS BOUND BY: A. 51-03.30N 156-22.20E, 50-43.10N 156-52.00E,…
Navigation prohibited until 151200Z may in areas bound by: a. 51-03.30N 156-22.20E, 50-43.10N 156-52.00E,… →
Earliest in the archive
- NOAAORR-6835 · Spills · Gulf of Mexico1991-09-06
…Coast Guard (USCG) Federal On-Scene Coordinator (FOSC) ordered the Intracoastal Waterway closed to all traffic and authorized placing hard boom across it in several locations. With boom in place, the…
High island, texas →
Often in the same message
Related terms
- Safety zone / exclusion zone
- An area ships must stay out of, or may only enter with permission, for safety or security.
- Anchoring and fishing prohibited
- Ships may pass but must not anchor, trawl or put gear on the seabed — usually because of cables, pipelines, moorings or ordnance.
Warning types that use it
- Restricted — Navigation prohibited, exclusion and security zones, ports closed to traffic.
- Storms — Hurricanes, typhoons and tropical storms: forecast cones from the U.S. National Hurricane Center and the Joint Typhoon Warning Center, and the port closures NAVAREA coordinators broadcast for them.
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.