A method for setting at least one transmission parameter of a transmitter of an underwater communication device, with the following characteristics: a) the method uses a transmitter with a computer and a modulator , in such a way that the modulator influences a transmission amplifier connected to a transmission converter and in such a way that the computer also has a demodulator connected to a receiving hydrophone via an intermediate reception amplifier , b) in the computer , a transmission message with a transmission check value is compiled, c) in the modulator , the transmission message is modulated while obtaining a signal, d) the signal is transmitted with the transmission converter , e) the transmitted signal is modified by the transmission medium, f) the modified signal is received by the receiving hydrophone , g) in the demodulator , the modified signal is demodulated while obtaining a demodulated message, h) a demodulated check value, which is compared with the transmission check value, is determined from the demodulated message in the computer , i) if the demodulated check value and the transmission check value match, after a content check of the demodulated message with the transmission message the at least one transmission parameter is retained for further transmission tasks, or is modified with a view to optimizing the data rate and/or emission rate for the next transmission, j) however, if the demodulated check value and the transmission check value or the demodulated message and the transmission message do not match, the at least one transmission parameter is changed with respect to robustness and the transmission message is retransmitted with a changed transmission parameter or changed transmission parameters. a) the method uses a transmitter with a computer and a modulator , in such a way that the modulator influences a transmission amplifier connected to a transmission converter and in such a way that the computer also has a demodulator connected to a receiving hydrophone via an intermediate reception amplifier , b) in the computer , a transmission message with a transmission check value is compiled, c) in the modulator , the transmission message is modulated while obtaining a signal, d) the signal is transmitted with the transmission converter , e) the transmitted signal is modified by the transmission medium, f) the modified signal is received by the receiving hydrophone , g) in the demodulator , the modified signal is demodulated while obtaining a demodulated message, h) a demodulated check value, which is compared with the transmission check value, is determined from the demodulated message in the computer , i) if the demodulated check value and the transmission check value match, after a content check of the demodulated message with the transmission message the at least one transmission parameter is retained for further transmission tasks, or is modified with a view to optimizing the data rate and/or emission rate for the next transmission, j) however, if the demodulated check value and the transmission check value or the demodulated message and the transmission message do not match, the at least one transmission parameter is changed with respect to robustness and the transmission message is retransmitted with a changed transmission parameter or changed transmission parameters. <EOS>