Notice: Changes to the USCG Local Notice to Mariners (LNM) and Light Lists
The U.S. Coast Guard Navigation Center announces upcoming changes to the Local Notice
to Mariners (LNM) and the Light List, as part of our efforts to modernize and improve the
accessibility, accuracy, and overall user experience for mariners and other stakeholders.

What Is Changing?

1. Transition From Paper Charts: In January 2025, NOAA will discontinue the production
of all paper charts. In alignment with this change, the Coast Guard will transition from
using NOAA Paper Chart Numbers and Editions/Dates for disseminating Marine Safety
Information (MSI) to using Official Waterway Names.

2. How You Will Access LNMs and Light Lists: The LNM and Light List data will now be
available in a geospatial format, which will allow you to visualize information interactively
on a map/chart. You can use your mouse wheel or the +/- buttons in the upper left portion
of the screen to zoom in or out and navigate to your desired area on the map/chart. Once
the area is displayed, you can generate a PDF of the LNM or Light List for that specific area,
which you can then save and/or print. Alternatively, you can use a fillable form on our
website to select your waterway by name from the Light List and generate the LNM or Light
List.

3. LNM and Light List Data Refresh Rate: LNM data will be refreshed every fifteen
minutes. Light List data will be refreshed every 24 hours. This will give you a much more up-to-
date operating picture, designed to enhance your efficiency and improve safety in your
area of transit or planned routes.

4. Elimination of Weekly Files: Weekly LNMs, Weekly Light List Correction Files, Daily
Discrepancy Files, and the Summary of Light List Changes will no longer be published to
focus on providing the most up-to-date and accessible format. In the near future, we will
also publish an Application Programming Interface (API) for interested parties to access the
data externally.

Why Are These Changes Being Made?
The modernization of MSI delivery is designed to improve the U.S. Coast Guard’s aid-to-navigation
data management and dissemination capabilities. By providing frequent
updates, geospatial visualization, and digital access, we hope to achieve our goals of:
• Enhancing Maritime Safety: By delivering the most current and precise information,
mariners can make better-informed decisions, reducing the risk of accidents and ensuring
safer navigation.
• Improving Accessibility: The shift to geospatial visualization makes it easier for all users,
from commercial mariners to recreational boaters, to stay informed.
• Increasing Efficiency: The integration of LNM and Light List data into a geospatial format
to simplify the gathering of safety information and facilitate easy route planning.
When Will These Changes Take Effect?
The transition to the modernized LNM and Light List platform (the Navigation Center
website) will be completed by Monday, October 21st.
How to Access the New Features?
Starting October 21st, 2024, you will be able to access the updated Local Notice to
Mariners (LNM) and Light List through the NAVCEN website, with a User Guide available to
assist you. While legacy versions of these products will no longer be produced or posted
after October 31st, previously available versions will remain accessible for download
indefinitely. Additionally, users can now generate updated LNMs in real time, with data
refreshed every 15 minutes.

For any questions or assistance, please visit our Contact Us page, select ‘LNMs or Light
Lists’ from the Subject dropdown, and submit your inquiry.

Thank you for your continued support as we work to enhance the safety and efficiency of
maritime navigation.

U.S. Coast Guard Navigation Center (www.navcen.uscg.gov)