Abstract— We study simulation of underwater communications using acoustic signals impaired by attenuation and multipath propagation. Attenuation is sensitive to the sourcereceiver separation distance, sound speed profile and signal frequency. Multipath propagation is affected by reflection and refraction due to the environment boundaries, sea surface and seabed, and sound speed profile. Simulation of attenuation together with multipath propagation is approached by translating acoustic signals from the time domain to the frequency domain, applying attenuation on frequency components and translating attenuated frequency components back into the time domain. This algorithm is repeated for each copy of a signal created due to multipath propagation. Using this approach, we have developed a simulation of underwater acoustic data signals. The implementation has been done using the MATLAB and the BELLHOP software. Simulation results have been obtained and are compared with a universal mod...