Croatian Navy The Croatian Navy ( Croatian : " Hrvatska ratna mornarica " ) is a branch of the Croatian Armed Forces . History . The modern Croatian navy was born during the Croatian War of Independence in 1991 . Commemorating the naval battles in September 1991 , but also as the day when the fleet of medieval Croatian duke Branimir defeated the Venetian navy on September 18 , 887 , the Day of the Croatian Navy is commemorated yearly on September 18 . The contemporary origins of the navy are in the Austro - Hungarian Navy , as well as the navy of Yugoslavia , whose 35 ships and various depots were seized during the war . Purpose . The mission of the Croatian Navy ( HRM ) is to defend the integrity and sovereignty of the Republic of Croatia , to promote and protect its interest in the Adriatic Sea , islands and coast - lands . It carries and organizes the naval defense of the Republic of Croatia . The Croatian Navy fulfils its role by preparing itself and carrying out the following main tasks : Structure of Croatian Navy . The following commands were created to carry out the mission of the Croatian Navy : Naval equipment . Fleet . Missile boat s Patrol boats Landing craft - Minelayer Armed Landing Craft Minehunter School ship Salvage Ship Current fleet status . Two former " Helsinki " class missile boats , FNS " Oulu " and FNS " Kotka " , were acquired from Finland . They were renamed " Vukovar " and " Dubrovnik " respectively , and entered service in December , 2008 . They were acquired along with a considerable amount of spare parts ( most notably three MTU engines - to be installed on " Kralj " class vessels ) due to a severe shortage of vessels at present . The price of these ships was €9 million and is considered rather symbolic , mostly because it was a part of the offset deal for the previous Croatian acquisition of Patria AMV armoured vehicles . The ships reached their full operational capability in June , 2009 and are set to remain in service until at least 2022 . They may undergo an anti - aircraft systems ' upgrade . The " Končar class " missile boat " Šibenik " has been overhauled with new turbine engines and radars and is due to remain in service until 2018 - 2020 . The " Kralj " class vessels were planned to be extensively modernized at a price of €20 million , but as a result of the recent acquisition of " Helsinki " class boats , they will probably undergo just an overhaul and an engine replacement , believed to be worth around €5 million per each ship . Four patrol boat s currently in service have been upgraded with new radar and the stern anti - aircraft gun has been replaced with a hoist for a semi - rigid inflatable . These are to be augmented and eventually replaced by an entirely new class . Construction of the first out of the projected 5 vessels ( more to follow later on ) was scheduled to start in 2007 , however the international tender for the construction of 1 + 4 vessels was published only on April 24 , 2013 . The tender calls for the acquisition of a total of 5 inshore patrol ship which are to be 42 meters long , with a displacement of roughly 220 tons and a maximum sustained speed of at least 28 knots . They are to be armed with a 30 mm Remote weapon station as their main armament along with two 12 , 7 mm heavy machine guns and a MANPADS launcher . The tender is to be finalized by late May 2013 and the construction of the first ship is to start in the last quarter of the same year . As projected , the first vessel is to enter service in early 2015 , the second one in 2016 , the third and the fourth in 2017 and the last one in 2018 . Units are projected to cost around 10 million euros respectively . Previously reported plans for the purchase of 2 - 4 offshore patrol vessels / surface combatants have been delayed for the time being but as stated by the MoD , the Navy is to continue developing its anti - surface and anti - shipping capabilities .