LNM FREQUENTLY ASKED QUESTIONS
What is a Local Notice To Mariners (LNM)?
The LNM is the primary means for disseminating information concerning
aids to navigation, hazards to navigation, and other items of marine
information of interest to mariners on the waters of the United
States, it's territories, and possessions. These notices are essential
to all navigators for the purpose of keeping their charts. Light
Lists, Coast Pilots and other nautical publications up-to-date.
These notices are published weekly. The LNM's are available on the World Wide Web. Vessels operating
in ports and waterways in several districts will need to obtain
the LNM's from each district in order to be fully informed.
How does the Coast Guard develop an LNM?
Each Coast Guard District is responsible for developing and issuing
LNMs. LNMs are developed from information received from Coast Guard
field units, the general public, the Army Corps of Engineers, U.S.
Merchant Fleet, National Oceanic and Atmospheric Administration
(NOAA), National Ocean Service (NOS), and other sources, concerning
the establishment of, changes to, and deficiencies in aids to navigation
and any other information pertaining to the safety of the waterways
within each Coast Guard District. This information includes: Reports
of channel conditions, obstructions, hazards to navigation, dangers,
anchorage's, restricted areas, regattas, information on bridges
such as proposed construction or modification, the establishment
or removal of drill rigs and vessels, and similar items.
What are LNM enclosures?
Enclosures contain NOS chartletts of a local area of tabulations
of controlling depths, excerpts from Code of Fed regulations regarding
marine laws or regulations, marine events, Corps of Engineer report
of channel condition survey sheets, Coast Pilot corrections, and
What is a Coast Guard Light List?
The Coast Guard Light Lists are published in seven volumes covering
the U.S. Coasts, the Great Lakes, and the Mississippi River System.
These are complete listings of all lights, buoys, daybeacons, ranges,
fog signals, radiobeacons, and radar beacons (RACONS); detailed
information is given on each aid including position (where necessary),
shape, color, and characteristics. In addition, each Light List
volume contains introductory pages with general information on aids
to navigation and their use, and the GPS, DGPS, and LORAN- C radionavigation
systems. Each volume is republished annually, but during the year
should be kept continuously corrected from the Local Notice to Mariners.
Coast Guard Light Lists are sold by the Superintendent of Documents,
U.S. Government Printing Office (GPO), Washington, DC 20402, by
GPO Bookstores and by GPO sales agents.
What is a Light List Number (LLNR)?
Light List numbers are assigned to all aids to navigation in order
to facilitate reference in the Light List and to resolve ambiguity
when referencing aids. Aids are tabulated in the same sequence as
lights are numbered - basically, clockwise around the U.S. Coasts
from Maine to Florida to Texas, California to Washington, east to
west on the Great Lakes, and upriver in the Mississippi River System;
seacoast aids are listed first in the applicable volumes, followed
by harbor and river aids, and then Intracoastal Waterways aids,
What is a Coast Pilot?
Just as for aids to navigation, charts are limited in what can
be shown by symbols and abbreviations regarding channels, hazards,
winds and currents, restricted areas, port facilities, pilotage
service, and many other types of information needed by a navigator
for safe and efficient navigation. These deficiencies are remedied
by the Coast Pilots published by National Ocean Service (NOS). U.S.
Coast Pilots are published in nine volumes to cover the waters of
the U.S. and it's possessions. They are of great value to a navigator
when used with charts of an area both during the planning stage
of a voyage and in the actual transit of the area.
Where do I obtain Nautical Charts?
The principal U.S. Agencies involved with nautical charts are the
Ocean Service (NOS) and the National
Imagery and Mapping Agency (NIMA). Both of these agencies have
branch or regional offices, plus a network of local sales agents
from whom charts and other publications can be obtained. Charts
or "navigational maps" of some inland rivers, primarily
the Mississippi, Ohio, Tennessee, and their tributaries, are prepared
by the Army
Corps of Engineers. Such charts or maps are normally purchased
from District Engineer Offices. The FAA also maintains their own
list of aeronautical and nautical authorized
chart sales agents.
How do I know what Chart to use?
Nautical charts can provide a navigator with a vast amount of information
including the depth of the water and objects under and on the surface,
features of the land, man-made features, information on tides and
currents, facilities ashore, and restrictive laws and regulations,
and more. Charts are published with an edition number and the date
to which the information it contains has been corrected. The NOS
and DMAHTC publish chart catalogs consisting of various pages or
panels showing the area covered by each chart.
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