The Search and Rescue Service at Sea in the Republic of Croatia consists of the Search and Rescue Service Headquarters, the National Search and Rescue Coordination Center, the Search and Rescue Sub-Center (Port Authorities of Pula, Rijeka, Senj, Zadar, Šibenik, Split, Ploče and Dubrovnik), coastal observation units (port offices of all harbour master’s offices, coastal radio stations, guarded lighthouses and observation stations of the Croatian Navy), and search and rescue units (naval, air and land units.). The main tasks of the National Center for Coordination of Search and Rescue at Sea are to coordinate search and rescue operations at sea, to monitor maritime traffic and control the safety of navigation and to coordinate actions in the event of sudden marine pollution. The National Headquarters – MRCC Rijeka, all sub-headquarters (harbour master’s offices) and their port offices, and all coastal radio stations (Rijeka radio, Split radio and Dubrovnik radio) maintain a maritime radio vigilance service on internationally established frequencies and channels for danger, urgency and safety all in accordance with the world maritime system of distress and safety. The National Center for Coordination of Search and Rescue at Sea and a sub-center for search and rescue (Harbour Master’s Office Rijeka) are situated in Rijeka, in the Harbour Master’s Office.