Before revision: A notice to mariners ( NTM or NOTMAR,) advises mariners of important matters affecting navigational safety, including new hydrographic information, changes in channels and aids to navigation, and other important data.
After revision: A notice to mariners ( NtM or NOTMAR,) advises mariners of important matters affecting navigational safety, including new hydrographic information, changes in channels and aids to navigation, and other important data.