Marine Glossary

|| || || || ||

Local Notice to Mariners

A weekly publication of the USCG district offices that reports on the status of aids to navigation (lights, buoys, electronic aids, day marks, etc.) along with other news from the USCG pertinent to safe navigation. Abbreviated LNM.

The LNM underwent a major format change in early 2025, after all traditional NOAA paper charts were discontinued. For one, they no longer refer to chart numbers, which was previously a main form of organization and they have now these new categories of announcements:

• Federal Discrepancies
• Federal Discrepancies Corrected
• Private Discrepancies
• Private Discrepancies Corrected
• Temporary Changes
• Additional MSI Categories (Marine Safety Information)
Hazards to Navigation
Marine Events
Bridges
Marine construction (excluding bridges)
Naval activity
Threatened and Endangered Species Advisory
MSIB (Marine Safety Information Bulletin)
Miscellaneous

They are now organized by date and by region, with the important improvement of using real dates rather than the historic practice of using week numbers. They can be downloaded as PDFs by USCG districts. Archived copies are also available.

See also Broadcast Notice to Mariners and note on Canadian Notices given at the end of this section.

Once a month the weekly issue is called a Monthly Edition. These are basically the same as the weekly ones, except with perhaps an expanded section on general news. The monthly issues are numbered sequentially within the sequence of weekly ones.

There is also an annual issue called Special Notice to Mariners. This is a particularly useful publication that covers navigational matters unique to the region, along with various safety information and services in the region. This special issue is available on request from the USCG, independent of the Local Notices. It is an entirely different type of document than the Local Notices.

The latest LNM can be downloaded from the USCG Navigation Center.

The Defense mapping Agency also publishes a set of Notices to Mariners that cover international waters.

-------------------------

The Canadian government also has a set of Local Notices to Mariners. Call: (613) 990-3037 or fax (613) 991-4982 for mail list information. Their notices are available by BBS, but special software is required. See Source Book, or by internet see http://www.coast.com/notmar. The Canadian Light List and Radio Aids to Navigation are also available on line at that address.

------------------------

Note that there is no marine weather covered in the notices, except insofar as a recent storm might have affected the local aids to navigation.

An abbreviated form of the Local Notice to Mariners is also broadcast daily on VHF radio, announced on channel 16 and then given on channel 22. These are called Broadcast Notice to Mariners. They are typically broadcast twice a day, 12 hours apart. Call your local district office for the schedule or they are also listed in Radio Navigational Aids in the section called Navigational warnings, section United States. Neighboring USCG stations will typically have the broadcasts about 1 hour apart. The times of broadcast also change by 1 hour during daylight saving time. Other nations have similar broadcasts.

Broadcast Notice to Mariners are also transmitted in text form in the NAVTEX broadcasts. They are referenced as, for example, BNM 0275-95 which would mean this is the 275th such announcement from that USCG district for 1995. Samples are given in the Source Book under NAVTEX.

See also Notice to Mariners, which is the DMA version for foreign waters.