© 2021 Elsevier LtdDue to their chaotic nature, underwater communication channels contain many adverse factors affecting the communication link quality and its performance. These adverse effects directly affect the data transfer between the source and the receiver. Absorption loss, which is one of these adverse factors, depends on depth, temperature, salinity, pH, and speed of sound, as well as frequency, and it has direct impact on the bandwidth used by the system and the distance required for reliable communication. In this study, the effects of variation of temperature, salinity, depth, and sound velocity on the channel bandwidth, channel capacity, and transmission power of the channels formed in the underwater environment in Erdek/Turkey were examined. Within the scope of the study, estimations of the bandwidth, capacity and transmission power parameters were conducted by using temperature, salinity, and sound velocity data relative to the depth recorded between July 2018 and December 2018. Cylindrical, spherical, and practical propagation models are used to compute the propagation loss. In contrast to the studies performed in the literature regarding absorption loss calculations, instead of using only the frequency-dependent approach, realistic models were created by including the effect of changes in the underwater environment in the channel estimation calculations using measurement data. Simplified absorption loss parameters for absorption loss calculations are proposed in the study. It was observed that the channel estimated within the scope of the study are compatible with the outputs obtained from the analysis.