## 3 Results and Discussion  
The result of the procedure for the harmonization of the laser scanning and bathymetric survey spatial data is shown in Figure 8. Due to the thematic nature of the study, the T3 DMI visualization has been provided with an appropriate legend, presenting important objects from the viewpoint of the marina's management. The grid of meridian and parallel images allow for the orientation of the presented content. The numerical model of the bottom of the basin has been enriched with labeled isobaths. Figure 7: Gauss-Kruger projection of the world (**a**) and Central and Eastern Europe for the 19\({}^{\circ}\) E meridian (**b**). The above form of data presentation significantly increases the possibilities of interpretation. Three-dimensional space of the mapping and its content are adapted to current needs. The unique features of the presented type of 3D space imaging show a much higher degree of realism in their projection. The use of state-of-the-art measurement techniques ensured a high reliability of the source data and faithful representation of objects. As a result, the elements presented in the T3 DMI image do not come from manual insertion in a graphics program, but from measurement. The exception here are labels indicating the location of selected marina points. Another feature of T3 DMI imaging is the presence of elements that are unusual for other mappings. In this case, they are scanned parts of the yachts. The grid of meridians and parallels situated below the surveyed data provides the mapping user with geographical orientation in space. The above elements can also be a valuable material for presenting the environment in other navigational applications, e.g., car or tourist. Figure 8: Three-dimensional map imaging (T3 DMI) visualization of the National Sailing Centre (NSC) marina. A feature of the T3 DMI is the user-customizable view. Depending on needs of the viewer, the orthogonal or perspective projection is available. The top orthogonal view of the T3 DMI model, combined with the parametric lines of the coordinate system and after adding the optional element of a linear scale, permits the creation of an image which corresponds with classic thematic maps [13]. The added value of the T3 DMI to a two-dimensional map is the possibility of changing to a perspective view with the desired position of the projection center [38]. Adding the possibility of placing additional descriptive objects in the three-dimensional space of the model, the user gains the option of creating projections focused on a specific aspect of space. In both cases, based on the three-dimensional model, the obtained graphic datasets can be used in analog paper form or electronic graphic files. When discussing the features and benefits of T3 DMI, it is important to mention the related matter of Virtual Reality (VR). The rapid development of the technology of measuring devices, hardware computer components, firmware, and software has contributed to the creation of a new way of presenting graphic data-- to replace monitors with VR headsets. Combined with the appropriate inertial sensors, a user obtains a unique experience that significantly differs from viewing the screen of a typical monitor. Many researchers were involved in the comparison and evaluation of VR sets, eg. [PERSON] et al. [39] or [PERSON] and [PERSON] [40]. Throughout the literature, there are publications which present the methodology behind creating three-dimensional models and displaying them in VR technology. [PERSON] and [PERSON] [41] presented the results of the study using a combination of TLS and photogrammetric technologies. An important element of the study was the creation of models based on point clouds. As a result, three-dimensional visualizations of the object were obtained, whereby the user can virtually relocate in the area with the use of a VR headset. In another study, [PERSON] et al. [42] presented the application of this technology in a revitalized post-industrial area.