The aim of this paper is to analyze the granting of State aid to maritime freight lines for the purpose of smooth running of regular maritime transport. Maritime transport with the obligation to provide public services falls under sectoral services of general economic interest. These include services of general interest for which there is no interest of the private, for certain parts of the population who, due to traffic isolation or distance, are difficult to meet the basic life needs. In these services, the State is obliged to finance the provision of services and to cover the overpayments due to the real needs and market failure. State aid funds are secured from the state budget and are distributed to all ministries controlling part of the budget within their jurisdiction. The Agency for Coastal Maritime Traffic is a non-profit legal entity operating within the Ministry of the Sea, Transport and Infrastructure, with the primary obligation to announce public tenders for selecting the shipping company to provide the transport service, and overseeing the execution of concluded contracts, payment of concessions and payments support. This paper outlines the types of aid and the conditions under which state aid can be allocated to a particular sector, service or business. Of crucial importance is the continuation of the subsidization of ferry, ship and freight lines with the obligation of public transport services that are not able to perform the service on a market-by-market basis. In addition to the great impact on the economic, demographic and economic development of the whole country, state aid affects the stopping of depopulation and stagnation of the island and greatly increases the quality of life of the island population.