Abstract: The knowledge of the location, shape and other characteristics of spatial objects in the coastal areas has a significant impact on the functioning of ports, shipyards, and other waterinfrastructure facilities, both offshore and inland. Therefore, measurements of the underwater part of the waterside zone are taken, which means the bottom of the water and other underwater objects (e.g. breakwaters, docks, etc.), and objects above the water, such as the above-water part of the waterside, breakwaters, hydraulic constructions, and other objects of the waterside infrastructure. In this paper, project results of an integrated acoustical-optical system for inventory of hydrotechnical objects are presented. The aim of the project was to elaborate a mobile underwater scanning system which could be applied in various works that require precise, detailed and coherent, underwater and above-water measurement, especially in areas associated with surveying, inspection and monitoring of objects in coastal areas.