The Class B Automatic Identification System (AIS) is a communications system for exchanging information, such as a vessel's position.
The Class B AIS is used primarily on leisure and recreational boats and on yachts. It can transmit data such as the boat's position, speed and course.
The AIS uses VHF frequencies to transmit and receive information. Thus, it has the same range as other VHF radios. Most AIS use TDMA transmission.
The Class B AIS cannot be used on merchant vessels. It transmits using about two watts of power, giving it less range than the Class A AIS.
