The Role of USCG Local Notice to Mariners in Boating Safety

Boating is a beloved pastime and a vital mode of transportation for many, but the waterways are constantly changing. From shifting sandbars to temporary construction zones, hazards can emerge quickly and without warning. That’s where the U.S. Coast Guard’s Local Notice to Mariners (LNM) comes in: a critical tool for ensuring safe navigation.

What Is the Local Notice to Mariners?

The Local Notice to Mariners is a weekly publication issued by each U.S. Coast Guard district. It provides updates and alerts about:

• Changes to aids to navigation  (buoys off station and lights not working)
• Dredging operations and underwater obstructions
• Bridge construction or closures
• Marine events that may affect traffic (e.g., regattas, fireworks)
• Temporary safety zones or restricted areas

These notices are tailored to specific regions, allowing boaters to stay informed about local conditions that could impact their route.

An excerpt from a recent LNM for Marina del Rey

Title	Sub-Category	Description
Sector Los Angeles, Submerged Land Act (SLA) - Marina Del Rey / General /Marine Construction (Excluding Bridges) / Survey Operations	Marine Construction (Excluding Bridges)	The Woolpert Company will be conducting hydrographic surveying between the period of 01 May, 2025 – 31 July, 2025 near Santa Monica, CA. The survey personnel and equipment spread will consist of one commercial survey boat approximately 33 feet in length, with a marine surveyor / technician / environmental monitor, a vessel mounted 3D multi-beam sonar system, and commercial grade differential GPS with sub-meter accuracy or better. Survey Vessel name/number: Taku/CF 3078 UK

Why LNMs Matter for Boating Safety

Whether you're a seasoned sailor or a recovering landlubber, LNMs are essential for: 

• Avoiding accidents: Knowing about submerged hazards or missing buoys helps prevent collisions and groundings.
• Route planning: Mariners can adjust their course based on construction zones or closed waterways.
• Regulatory compliance: Staying updated ensures boaters follow temporary rules and avoid fines.
• Emergency awareness: Notices may include alerts about search and rescue operations or environmental hazards.

In short, Local Notices to Mariners are like traffic reports for the water - keeping everyone informed and safe. 

How to Access Local Notices to Mariners

For the Coast Guard’s Southwest District, which covers California as well as Arizona, Nevada, and Utah, you can find the weekly LNMs here: https://tinyurl.com/SWD-NoticeToMariners

For even more up-to-date information, you can sign up for email notifications at https://tinyurl.com/SWD-NTM-Email

You can also view and download LNMs from the USCG Navigation Center. The site allows users to:

• Select their Coast Guard district
• Search by waterway or category
• Subscribe to weekly updates

There’s even a new interactive interface that lets users define their own area of interest using GIS tools.

Final Thoughts

The Local Notice to Mariners isn’t just a bureaucratic bulletin; it’s your lifeline for safe and responsible boating. By checking LNMs before heading out, sailors can navigate with confidence, protect their boats, and safeguard lives.