Maritime transport is of great importance to our country as it is one of the most important branches of overall transport and a fundamental factor in connecting the world. Geo-traffic position with very frequent traffic of all types of ships of different sizes and cargo makes the Adriatic sea an ecologically very sensitive area. The possibility of pollution of the Adriatic is increasing every year, since maritime traffic is constantly increasing, and therefore the possibility of pollution that threatens natural habitats in the area of waterways and around seaports is increasing. Any pollution from ships affects, above all, marine organisms, and therefore food and human health, and because of the emissions, pollution also affects the climate. For this reason, the conservation of the Adriatic ecosystem and the prevention of the devastation and degradation of the ecological resources of the marine and coastal areas are of particular importance. Based on proven research, it has been concluded that „high-risk“ pollution vessels are primarily those not subject to the Marpol Convention and not obliged to process sewage, which were sought and kept along the coast, such as yachts, sailboats or small boats and cruise ships under the croatian flag. Cruisers must have purified sewage water and no untreated water should be released into the coastal seas so they were not so polluting. But while environmental incidents are becoming more common, the Adriatic is still considered one of Europe's cleanest seas.