Aids To Navigation
How is AIS used on aids to navigation?
AIS transmitters can also be affixed to a floating or fixed aid to navigation (ATON), such as a buoy, beacon, or light. The AIS broadcast provides the position and purpose of an aid, such as a port or starboard lateral buoy, even before it is close enough to be visible from a ship or to provide a radar return. This can help mariners confirm their ship's position or to prepare to make a turn that is based on passing a particular aid.
Three types AIS ATONs
- Real AIS ATON - A physical aid to navigation structure on which an AIS transmitter is affixed and from which AIS messages are broadcast.
- Synthetic AIS ATON - A physical aid to navigation structure, without an AIS transmitter, but for which AIS messages are broadcast from another (usually land-based) location.
- Virtual AIS ATON - An aid to navigation with no physical structure. It exists only through AIS messages broadcast from another location. A few uses of virtual ATONs include environments where buoys are moved seasonally, such as in sea ice, or where a marker needs to be placed quickly, such as to mark a newly identified isolated danger or wreck. These aids can only be seen on an Electronic Chart Display and Information System (ECDIS), or other AIS enabled display, such as a ship’s radar.
AIS ATONs on NOAA nautical charts are portrayed with a magenta circle, enclosing an ATON symbol. The same symbol is used to depict both real and synthetic AIS ATONs, with a magenta “AIS” label next to the circle. Virtual AIS ATONs have a “V-AIS” label. The table below shows examples of how non-AIS and AIS ATONs are shown on NOAA nautical charts.
used in U.S. territories in the South Pacific, the square and triangle top marks shown on V-AIS aids are switched with each other.
The USCG Light List also identifies AIS aids. For example, for this safe water mark 
, the USCG light list entry provides information regarding the AIS message in the remarks column, as shown below.
ECDIS and NOAA paper nautical charts portrayal of the most common types of virtual AIS aids are shown in the table below.
*References from National Oceanic and Atmospheric Administration (NOAA) and United States Coast Guard (USCG)