Mr. sc. Maja Markovčić Kostelac is the director of the Croatian Shipowners’ Association for international navigation Mare Nostrum. She was born in Zagreb in 1966. She graduated from the Faculty of Law, University of Zagreb in 1990. In 2008 she obtained her LL.M. in maritime law and law of the sea at the Faculty of Law, University of Split, with the topic Implementation of the International Convention on Ballast Water 2004 in closed and semi-enclosed seas, with special attention to the Adriatic. From 1990 to 1993 she worked in the Zagreb City Assembly on activities relating to international cooperation and protocol, and from 1993 to 2014 she worked in the Ministry of Maritime Affairs as a consultant, Head of Department for International and Legal Affairs, Head of Maritime Safety, Acting Director of the Directorate of Maritime Affairs, and Head of the Sector for Maritime Navigation, International and Legal Affairs. She has been employed in Mare Nostrum since April 2014 as Director of the Association, and her activities pertain to the promotion of the interests of Croatian shipping and the development of navigation in general. She has attended numerous diplomatic conferences as leader or member of the Croatian delegation, as well as board meetings of the International Maritime Organization and the International Labour Organisation. In addition, she was co-chairman of the Conference of States Parties to UNCLOS Convention, and participated in the preparation and negotiations for the conclusion of bilateral international maritime agreements, and in the negotiations for Croatian accession to the EU in the field of maritime affairs (Chapter 14 and Chapter 21). She worked on the preparation of almost entire Croatian maritime legislation, in particular the Maritime Code, the Act on Ports and the Maritime Domain, the Act on the Security of Ships and Ports and a number of implementing regulations, as well as the law on the ratification of international conventions in the field of maritime affairs. She is a member of the Croatian Society for the Law of the Sea and the Maritime Council of the Croatian Academy of Sciences and Arts. She is the national coordinator of the GLOBALLAST Project for Croatia, and has participated as an expert in several international projects in the field of maritime affairs. She has worked as a lecturer at the Department of Maritime Studies at the University of Zadar, the Faculty of Law in Zagreb, and the Faculty of Maritime Studies in Rijeka. Also, she has lectured at the International Maritime Academy in Genoa and Malmo and given talks at several professional and scientific conferences in the country and abroad. She has published many scientific papers in the field of international maritime law, maritime safety and protection of the marine environment in domestic and international publications.