Abstract: One of the main applications of multi-beam sonars is high-resolution bathymetry measurement, as well as the detecting and imaging of underwater objects, such as shipwrecks. In order to ensure that the visual quality is good enough for the researcher to investigate the object in more detail, an approach relying on the construction of the three-dimensional model of an imaged object - e.g. consisting of nodes, edges and plane elements (facets) – is needed. Preceded by the short State-of-the-Art review, the applications of selected algorithms for three-dimensional seafloor-surface and underwater-object shape reconstruction have been presented. Two types of algorithms were investigated in the context of real-time application possibility; namely, raster height map, as well as 2D Delaunay triangulation. The presented preliminary results are promising both with respect to reconstructed 3D shape quality and to algorithm computational complexity, allowing for real-time mode applications.