Various activities, whether economic, social, or environmental, exert pressure on a coastal area. The extent of economic activities taking place in coastal regions is continuously increasing, particularly in tourism, maritime transport, port operations, and fisheries and aquaculture. Therefore, the decision to establish activities in a coastal area is complex and requires careful consideration by all stakeholders who use this space, which is potentially one of the most important natural resources for the development of any coastal country. This research is focused on assessing the justification for establishing economic activities in a coastal area, taking into account the interconnection of spatial, safety, environmental, and social factors. Therefore, three possible scenarios have been proposed: the location of the communal port, the location of the nautical port-marina, and the location of the marine entertainment and recreation centre. The goal was to develop a model that would enable the objective assessment and selection of the most suitable activity that would simultaneously benefit society and have the least harmful impact on the environment. Therefore, a multi-criteria analysis was conducted using the AHP (Analytic Hierarchy Process) method. The decision-making process was based on the expert validation of criteria, sub-criteria, and alternatives. An analytical tool called Expert Choice was used to synthesise the results and select the optimal activity. The sensitivity analysis confirmed the stability and reliability of the obtained results, with the AHP method proving to be an effective tool in structuring the decision-making process regarding the establishment of activities in the coastal area. Based on the results of the multi-criteria assessment, planning the establishment of activities is an important precondition for the long-term and sustainable development of coastal activities in an area.