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Broadcast Warningsspacer


In support of the Global Maritime Distress and Safety System (GMDSS), Broadcast Warnings are promulgated by the Worldwide Navigational Warnings Service (WWNWS) to provide rapid dissemination of information critical to navigation and the safety of life at sea.

Navigational Warnings are issued regularly and contain information about persons in distress, or objects and events that pose an immediate hazard to navigation. The four types of Navigational Warnings - NAVAREA IV, HYDROLANT, NAVAREA XII, and HYDROPAC - are categorized by their location.
View graphic of Navigational Warnings limits.

HYDROARC Warnings are issued for the Arctic region not covered by HYDROLANT and HYDROPAC messages. 

Broadcast Warning messages are also available as a Google Earth (.kmz) file: Download file.

The Navigational Warnings Prototype Web Map Application, can be used with a web browser to display a variety of Maritime Safety Information including in-force Broadcast Warning messages, Navigational Warning and SAR limits, and their Points of Contacts. The web-based Coastal Warning Input Form provides a capability for partners to enter and geospatially view their messages. The capability to add them and make them accessible in the Navigational Warnings Prototype Web Map Application is still under development.

The following two links provided below are for feature services that can be used as a source for web map, application, and mobile app development:
Navigational Warnings Prototype Feature Service
Navigation Stations and Rescue Areas Feature Service

As of 26 January 2017, the US Government's process for issuing maritime security alerts and advisories has transitioned to the US Maritime Advisory System, replacing Special Warnings and MARAD Advisories. The new system will issue notifications as US Maritime Alerts and US Maritime Advisories. Legacy Special Warnings and MARAD Advisories will remain available on this site until the transition effort is complete on 6 July 2017, unless cancelled sooner. New Alerts and Advisories are now available from the Maritime Security Communications with Industry (MSCI) Web portal.

The Daily Memorandum is issued each week day, excluding federal holidays, and contains a summary of all Broadcast Warnings and Special Warnings promulgated during the past 24-72 hours. The Atlantic Edition includes HYDROLANT and NAVAREA IV Warnings, while the Pacific Edition includes HYDROPAC and NAVAREA XII Warnings. Both editions include Special Warnings and HYDROARC Warnings issued during the same period.

Use the query form below to retrieve Broadcast Warnings from the on-line database.


  Current Warning Messages
Warning Type Current Warning
NAVAREA IV 1097 / 2017
NAVAREA XII 526 / 2017
HYDROARC 395 / 2017
HYDROLANT 3758 / 2017
HYDROPAC 4067 / 2017
Special Warnings 131 / 2015
MARAD Advisories 3 / 2016
   Daily Memorandum
 Atlantic Edition (4 KB)
 Pacific Edition (1 KB)
Last Database Update Occurred: 221612Z NOV 2017
Warning type to Query: Query Directions