AIDS TO NAVIGATION (ATON)

Charts and Safety Tips

• Charts are published by the National Oceanographic and Atmospheric Administration (NOAA) for the navigable waters of the United States. Chart Number One, published by NOAA, and available as a free download at nauticalcharts.noaa.gov/mcd/chartno1.htm explains every symbol and buoy meaning found on NOAA charts.
• Charts are mariners' guides to navigation. For areas where NOAA charts are not available, private companies such as GMCO produce local maps of inland lakes and rivers.
• Never pass too close to a buoy and don’t rely solely on a single Aid to Navigation to determine position, as buoys may shift from charted positions.
• The mariner who uses charts, understands the meaning of buoys, and learns of local hazards will be a safer, more knowledgeable boat operator.

Know the Local Area

Before casting off, it is extremely important to identify local hazards requiring special attention. Good sources of local information are marina operators, Harbor Masters and other boat owners. Another source is the USCG publication “Local Notice to Mariners” which lists construction hazards and other important local information.

When boating in an unfamiliar area, ask these questions to learn if there are unique local hazards:

• Are there low-head dams on the rivers? Find out the location of take-out (portage) areas above the dams.
• What are the class of rapids, areas of white water, wave heights, and current water levels?
• Are there localized sudden winds or wind sheers?
• What is the state of the local tides and currents?
• Are there overhead cables, bridges, or heavy boating traffic in certain areas?

Learn what hazards may be in the area where you boat and make preparations to avoid them. And don’t become complacent – water and its hazards are always changing. What once was a safe passage may now be a sand bar ready to grab your boat.

Interference with or Damage to Aids to Navigation

No person shall take possession of, make use of for any purpose, build upon, alter, deface, destroy, move, injure, obstruct by fastening vessels thereto or otherwise, or in any manner whatever impair the usefulness of any aid to navigation established and maintained by the United States.

U.S. Aids To Navigation System

The waters of the United States and its territories are marked to assist navigation by the U.S. Aids to Navigation System. This system employs a simple arrangement of colors, shapes, numbers and light characteristics to mark navigable channels, waterways and obstructions adjacent to these.

• Aids may be anything from lighted structures, beacons, day markers, and range lights, to floating buoys.
• Each aid has a purpose for determining location, getting from one place to another or avoiding danger.
• The U.S. Aids to Navigation System is intended for use with nautical charts published by NOAA.
• Charts show the coastline, buoys and beacons, depths of water, bridge heights, land features, directional information, marine hazards and other pertinent information.

Beacons

• Beacons are aids to navigation structures that are permanently fixed to the earth's surface. They range from lighthouses to small, single-pile structures and may be located on land or in the water.
• Lighted beacons are called lights; unlighted beacons are called daybeacons.
• Beacons exhibit a daymark to make them readily visible and easily identifiable.
• Generally, during daylight hours the daymark means the same as a light or reflector at night.
• Buoys (floating aids that come in many shapes and sizes) are moored to the seabed by concrete sinkers with chain or synthetic rope. Moorings of various lengths are connected to the buoy body. They convey information to the boater by their shape or color, by the characteristics of a visible or audible signal, or a combination of two or more such features.

Local Notice to Mariners (LNM) on the Internet

The USCG publishes the Local Notice to Mariners, (LNM), via the Internet at http://www.navcen.uscg.gov. The LNM provides weekly updates concerning navigable waters within a geographic area. Updates can include:

• Reports of buoys that are off-station or are not displaying proper lights (burned out lamps).
• Explanation and duration of dredging or construction projects.
• Location and duration of Marine Safety Zones as part of Home Land Security measures.