The prerequisite to achieve a high level of national security of coastal states is realised through the efficient supervision and the sea protection in order to reduce security threats and risks at sea. A significant importance carries the geographical and geostrategic deployment of coast guard maritime locations. This doctoral thesis examines and analyses relevant factors that have an impact on the effectiveness of control and protection of the rights and interests of coastal states in semi - enclosed seas. Semi - enclosed seas in the world are minutely explained. The thesis studies and analyses the organisation of relevant state administration bodies of the respective coastal state in the operational efficiency of the implementation of the control and protection of rights and interests in maritime areas. It synthesizes relevant cases of maritime border crossing violations. A thorough analysis of the safety of maritime transport is carried out. The thesis collects the result of ship, freight and passenger traffic in seaports and it provides an analytical comparison of dominant models of the organisation of coast guards in the world as well as the one of the respective country. Characteristics and limitations of the selected maritime locations in the respective semi - enclosed sea are systematically studied in relation to the spatial distribution. The proposed model for optimising the spatial distribution of coast guard resources is based on a multi criteria decision making method and is described by a mathematical multi criteria analysis model. The model integrates criteria and sub - criteria as the most important step in solving the research problem in order to result in a higher level of protection of national rights and interests of coastal states at sea. The optimisation model of the spatial distribution of coast guard resources in the semi - enclosed sea of the respective coastal state as a function of national security was developed through a systematic analysis of the defined multidimensional criteria, weighting coefficients, quantitative and qualitative measures. The crucial part of the research, realisation and development of a draft model in relation to the classical concept of spatial distribution of resources, is based on the use of the PROMETHEE methods for partial and complete ranking, GAIA method for a geometric display of results and Visual PROMETHEE Academic Edition software for the analysis of input data. The ranking of maritime locations enables the coastal state to plan and develop the maritime locations for the deployment of coast guard resources. IV It determines the priority of choice among the proposed maritime locations. The validation of the proposed optimisation model for the selection of maritime locations was carried out in northern and central geographical units of the Adriatic Sea - the eastern part although it is applicable to any other similar maritime location. The validation has confirmed the correctness of the created model since the proposed maritime locations have been ranked better in comparison to the reference ones (the existing ports) based on set criteria.