Three Parts to Remember
A geofence has three components that need to be specified by you, the user - a zone, a filter, and instructions for alerts. Take a moment to read through the concepts and instructions below. When you’re ready to create you’re geofence, go to the “Create a Geofence” page.
WHERE is your interest?
A zone is simply an area constrained by geographic coordinates. If you use Geographic Information System (GIS) applications like ArcGIS or Google Earth then you are probably used to seeing lines, circles, and polygons that designate areas of interest. The concept here is the same.
A polygon type geofence is created using an unlimited number of coordinates. The program will close the polygon by connecting your first and last coordinates with a straight line.
Because many organizations share common interests, several pre-designated options for zones are featured in the “Create a Geofence” section. You can also create your own zone by using GIS coordinates as described above. For simplicity, we ask that you enter coordinates in Decimal Degrees (DDD.DDDDD°) format.
WHAT is your interest?
Vessels broadcast AIS signals that carry specific bits of information (see image below), from the vessel’s name and unique numerical identifiers to its type, speed, and course. All of this information can be used to build a filter that allows only the types of vessels you specify to trigger alerts as they pass in and/or out of your zone.
ALERTS
When you set up a geofence you will be given the option to receive alerts by email or by text (SMS). In order to receive alerts by text you’ll need to know the name of your carrier.