AIS ship transceiver which is provided for installation in a ship in order to be able to transmit and receive AIS radio signals, comprising an AIS radio transmitting unit, which is designed for transmitting AIS radio signals (AIS1/AIS2, AIS3/AIS4), and comprising an AIS radio receiving unit which is designed for receiving AIS radio signals (AIS1/AIS2, message 4) which are emitted by adjacent ships and/or AIS base stations, located within range, the AIS ship transceiver being configured - after reception of an AIS base station message (message 4) emitted by an AIS base station, in dependence on the received AIS base station message (message 4), to deactivate the emitting of at least a part of the AIS radio signals (AIS3/AIS4) by the AIS radio transmitting unit and/or - after reception of an AIS base station message (message 4) emitted by an AIS base station, in dependence on the received AIS base station message (message 4), to activate the emitting of at least a part of the AIS radio signals (AIS3/AIS4) by the AIS radio transmitting unit characterized in that the AIS ship transceiver has a control unit which is connected to a database in which data with respect to valid AIS base stations are stored, the control unit being configured, - after reception of the AIS base station message (message 4), to validate the transmitting AIS base station in dependence on the data contained in the AIS base station message (message 4) and the data stored in the database for this AIS base station, and the control unit being furthermore configured, - for deactivating the emission of at least a part of the AIS radio signals (AIS3/AIS4) in dependence on the validation of the transmitting AIS base station, whereby in the case of a failed validation of the transmitting AIS base station, the emitting of the at least one part of the AIS radio signals is not deactivated, and/or - for activating the emission of at least a part of the AIS radio signals (AIS3/AIS4) in dependence on the validation of the transmitting AIS base station, whereby in the case of a failed validation of the transmitting AIS base station, the emitting of the at least one part of the AIS radio signals is not activated. - after reception of an AIS base station message (message 4) emitted by an AIS base station, in dependence on the received AIS base station message (message 4), to deactivate the emitting of at least a part of the AIS radio signals (AIS3/AIS4) by the AIS radio transmitting unit and/or - after reception of an AIS base station message (message 4) emitted by an AIS base station, in dependence on the received AIS base station message (message 4), to activate the emitting of at least a part of the AIS radio signals (AIS3/AIS4) by the AIS radio transmitting unit - after reception of the AIS base station message (message 4), to validate the transmitting AIS base station in dependence on the data contained in the AIS base station message (message 4) and the data stored in the database for this AIS base station, and the control unit being furthermore configured, - for deactivating the emission of at least a part of the AIS radio signals (AIS3/AIS4) in dependence on the validation of the transmitting AIS base station, whereby in the case of a failed validation of the transmitting AIS base station, the emitting of the at least one part of the AIS radio signals is not deactivated, and/or - for activating the emission of at least a part of the AIS radio signals (AIS3/AIS4) in dependence on the validation of the transmitting AIS base station, whereby in the case of a failed validation of the transmitting AIS base station, the emitting of the at least one part of the AIS radio signals is not activated.