An AIS aid to navigation (ATON) is any kind of navigational aid that is transmitted over the AIS radio. ATONs are displayed on the charts and have identifying information, such as position and type.

There are three main kinds of AIS ATONs. Real ATONs physically exist and send their identifying and location information from their actual location. Synthetic ATONs physically exist, and their identifying and location information is sent from another location. Virtual ATONs do not actually exist, and their identifying and location information is sent from another location.

You can view AIS ATONs on the chart when the chartplotter is connected to a compatible AIS radio. To show AIS ATONs, from a chart, select Options > Layers > Chart > Navaid > ATONs. You can view more information about an ATON if you select the ATON on the chart.

Symbol	Meaning
	Real or synthetic ATON
	Real or synthetic ATON: Topmark North
	Real or synthetic ATON: Topmark South
	Real or synthetic ATON: Topmark East
	Real or synthetic ATON: Topmark West
	Real or synthetic ATON: Topmark Special
	Real or synthetic ATON: Topmark Safe
	Real or synthetic ATON: Topmark Danger
	Virtual ATON
	Virtual ATON: Topmark North
	Virtual ATON: Topmark South
	Virtual ATON: Topmark East
	Virtual ATON: Topmark West
	Virtual ATON: Topmark Special
	Virtual ATON: Topmark Safe
	Virtual ATON: Topmark Danger