The Automatic Identification System (AIS) is a short range coastal tracking system used on ships and by Vessel Traffic Services (VTS) for identifying and locating vessels by electronically exchanging data via VHF radio.
Only large vessels are required to carry AIS. On Lake Ontario Coast Guard, and some Coast Guard Auxiliary, Police vessels and pleasure craft may also be equiped. The TOWARF Rescue Boat has an AIS system onboard.
The AIS map is provided by MarineTraffic. For more information about MarineTraffic and AIS, visit their FAQ.