Local Notice to Mariners (LNM)

An official publication issued by maritime authorities to inform mariners of temporary or permanent changes to navigational aids, hazards, or other critical information affecting local waters.

A Local Notice to Mariners (LNM) is a communication tool used by maritime authorities, such as harbourmasters or coastguards, to ensure the safety and efficiency of navigation in specific localised areas. These notices provide updates on a wide range of topics, including the status of buoys, lights, and other navigational aids, as well as information on dredging operations, underwater obstructions, construction projects, or changes to shipping channels. LNMs are typically issued on a regular basis, such as weekly, and are aimed at keeping mariners informed of any conditions that could impact safe passage.

Unlike Notices to Mariners, which often cover broader regions or national waters, LNMs are focused on specific local areas, making them especially relevant for vessels operating in coastal or inland waters. They are an essential resource for both commercial and recreational mariners, ensuring that charts and sailing directions remain up-to-date. Mariners are encouraged to consult these notices frequently, as they may contain time-sensitive information that is not immediately reflected in official nautical charts or publications.

The dissemination of LNMs has evolved with technology, and they are now commonly available online, allowing for easier access and distribution. However, the responsibility ultimately lies with the mariner to stay informed and incorporate this information into their voyage planning and navigation practices.