The paper considers a modeling algorithm and programs for calculating the attenuation of signals over the sea surface to provide remote control of unmanned ships in the waters of the port of Novorossiysk. Modeling of attenuation of broadband signals at the frequency of 900 MHz complies with the International Telecommunication Union Radio Communication Sector ITU-R P.1546, Okumura-Hata, Consultative Committee on International Radio communications, Free Space loss, the two-rays ground-reflection model and the three-ray model path loss. It is shown that for marine radio communication two-ray method of geometric approximation agrees well with the experimental data, while the introduction of a correction factor allows to obtain the most effective model of broadband signal attenuation in the line-of-sight zone.