Commercial vessels over 300 tons and all passenger vessels are required to have installed an AIS (automatic identification system). This equipment transmits the ships name, mmsi number, position, speed, course and heading every few seconds. AIS enables other vessels and port authorities to get an accurate overview of what is happening in their immediate area.
Move the mouse cursor over any map control, and click to select/activate, or move the mouse cursor over any ship icon, and click to display its information. If you use a wheel-mouse, you can also zoom in/out using the wheel. Double-clicking on a specific map area, will centre and zoom the map to that area.
You can drag the map by the click (mouse pointer changes to a fist) and drag method, or you can use the map overview (bottom right-hand corner of map) to click and drag the blue box anywhere you want, and the main map display will follow in step. The map information is automatically updated in real-time as indicated by the timer.
All range and bearing, and time-to-closest-point-of-approach (TCPA) values are calculated from the Welcome Islands (WEC) calling-in-point (CIP) for the Port of Thunder Bay (TUN).
AIS information is available at Shipplotter. For general map questions see Google Maps API.