Maritime Act Amendments of 2008 created a legal basis for establishing a vessel traffic monitoring and managment system (VTMIS). The VTMIS is established according to the EU Directive 2002/59/ establishing a Community vessel traffic monitoring and information system. The system should help to enhancing the safety and efficiency of maritime traffic. In this article the authors pay special attention to one task that fall within the scope of VTMIS - monitoring the safety of navigation. The authors analyze what is its role in determining the criminal liability for the breach of international and national safety of navigation provisions and standards in the coastal area of Croatia. They conclude that data provided by AIS system and other relevant equipment can be used as evidence in criminal proceedings. PUBLICATION ABSTRACT