What is AIS?
AIS will place a triangular icon on the chart plotter's screen that represents any vessel sending out AIS signals. This includes most commercial vessels, which are required by law to have it, as well as numerous recreational craft with owners who are discovering the safety benefits of AIS. Just place the chart plotter's cursor on an AIS icon, and a list of valuable information unfolds. The ship's name and radio call sign are shown. This means you can pick up a VHF and hail a specific vessel that may be posing a threat. Additional information includes the vessel's length, beam and draft, its exact position, speed and heading, its rate of turn and even the calculated closest point of approach (CPA) and the time it will happen (TCPA). Commercial ships often also transmit vessel type, port of origin, destination and even the type of cargo, including hazardous materials.