For pleasure craft used only for recreational or fishing purposes, there is no obligation to equip AIS transceivers.

However, since an AIS transceiver has many advantages on board, there are the so-called Class B AIS transceivers. Class B AIS transceivers are generally less expensive than class A transceivers because there are less strict requirements for their performance. Class B transceivers are reduced to the most important data. Often only the MMSI number of the vessel, the current position, course, and size of the vessel are transmitted. This makes the operation of class B transceivers very easy. The vessel name and the vessel dimensions must be programmed once, then the AIS transceiver is ready for use.

Class B AIS transceivers have a lower reporting rate than class A transceivers. Their maximum transmission power is 2W. While class A transceivers use a complex system (SOTDMA = Self Organising Time Division Multiple Access) to coordinate with other transceivers in the environment to occupy the transmission frequencies, class B transceivers usually simply use the free time slots to transmit their data (CSTDMA = Carrier Sense Time Division Multiple Access).

However, there are also class B AIS transponders that make use of SOTDMA technology. The transmission frequency of AIS data in class B transponders depends on the speed of the vessel and the frequency utilization and ranges from every 5 seconds to every 3 minutes.

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