Notice To Mariners (NtM) - Nautical Know How

An official publication announcing corrections or information affecting nautical charts and navigational publications.

Notices can provide permanent chart corrections, temporary or preliminary information, publication amendments and details of new or changed aids and hazards. Numbering, frequency, format and correction procedure depend on the issuing hydrographic office or competent authority.

A notice must be matched to the correct chart or publication edition and applied or recorded under an organised update system. It is distinct from an immediate radio navigational warning and from a local notice whose scope and legal purpose may differ.

Related Content:

UKHO — Notices to Mariners
Bottom-Up vs Top-Down: Pilotage Plans That Work
Bottom-up or top-down? After several practical courses with skippers trained elsewhere, I saw the same pilotage problems: plans too long to read or too thin to protect the boat. Here’s how to choose a format, avoid left/right flips, and build a cockpit-ready plan that works by day and at night.
Creating a Cockpit-ready Pilotage Plan
Navigating with Waypoints: Maximising Your Chart Plotter’s Potential
Notices to Mariners – RYA 3 & 4
Skipper’s Debrief: Turn Every Trip into a Better One
A simple 10-minute debrief that makes every passage better—what to ask, how to capture lessons, and how to fold them back into your next plan.

Notice to Mariners (NtM) (NM)

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