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
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.