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Broadcast Warningsspacer


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 file.

The Navigational Warnings Prototype Web Map Application, can be used with a web browser to display 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.

Feature services 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, maritime security alerts and advisories are issued by the US Maritime Advisory System, replacing Special Warnings and MARAD Advisories. The new system will issue notifications known as US Maritime Alerts and US Maritime Advisories. 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 Broadcast Warnings and Special Warnings promulgated during the past 24 to 72 hours. The Atlantic Edition includes HYDROLANT and NAVAREA IV Warnings, while the Pacific Edition includes HYDROPAC and NAVAREA XII Warnings.

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


  Current Warning Messages
Warning Type Current Warning
NAVAREA IV 813 / 2019
NAVAREA XII 443 / 2019
HYDROARC 213 / 2019
HYDROLANT 2797 / 2019
HYDROPAC 3013 / 2019
Special Warnings 131 / 2015
MARAD Advisories 3 / 2016
   Daily Memorandum
 Atlantic Edition (4 KB)
 Pacific Edition (1 KB)
Last Database Update Occurred: 131725Z SEP 2019
Warning type to Query: Query Directions