Abstract: The paper introduces two different methods of numerical computation of the time proceeding of low-frequency acoustic pulse reflected from layered sea bottom. The input of both mathematical models are time proceedings of known sampling pulses and parameters describing determined seabed structure. Parameters necessary for complete bottom description are number of sediment layers and mean grain size of specific type of sediment creating each layer. Two introduced approaches strongly differ from each other in complexity, computation time and domain, number of phenomenon taken into account in formal description of considered process. First of the presented methods is based on time analysis of sampling pulse propagation, second one treats the propagation media as a system characterized with given transmittance. The goal of introduced investigations is to estimate usefulness of results obtained with those two mathematical models for analysis empirical data gained using parametric echosounder for seabed structure examination.