Abstract <p>The maximum detection range for an underwater noise source in the presence of internal waves, conditioning the sound-field mode coupling, has been estimated in the framework of holographic processing of hydroacoustic broadband signals. The estimation was performed based on the results of numerical simulation of the sound field decay with distance and experimental data on the spectral characteristics of the noise emission of a moving underwater craft and the background interference of the water area. A single receiver and a linear portable antenna have been considered as receiving modules. The input signal-to-noise ratio at which the maximum detection range is attained is estimated. The probabilities of true detection at specified false alarm probabilities are calculated based on the Neumann–Pearson criterion for the input signal-to-noise ratio corresponding to the maximum detection range. A comparative analysis of the maximum detection range in the presence and in the absence of background internal waves is performed.</p>