Yugoslav minelayer Zmaj The Yugoslav minelayer " Zmaj " ( Dragon ) was built in Germany as a seaplane tender for the Royal Yugoslav Navy in 1928 – 30 . She does not appear to have been much used in that role and was converted to a minelayer in 1937 . Captured by the Germans in 1941 , she was renamed " Drache " ( Dragon ) and redesignated as an aircraft tender and later as a troop transport , before she was rebuilt as a minelayer in 1942 . She laid one minefield in 1943 that sank two Allied destroyers and badly damaged a third in the Aegean Sea . " Drache " was also used by the Germans to evaluate the shipboard use of helicopter s for reconnaissance purposes . She was sunk by Allied aircraft in 1944 at Samos and scrapped in place after the end of World War II . Description . Background . The Royal Yugoslav Navy operated a series of seaplane bases on the Dalmatian Coast before World War II and decided that it needed a ship to transport seaplanes between them and to rescue downed aircraft after operations as had been common during World War I . It decided on the smallest possible ship that could carry supplies and spare parts for ten seaplanes . General characteristics . " Zmaj " was long overall . She had a beam of and , at full load , a draft of . She displaced at standard load . Her two propellers were powered by a pair of eight - cylinder , four - stroke MAN Diesel engines that had a maximum output of . This was enough to propel her to a speed of . She carried a total of of fuel which gave her a range of . She lacked a traditional funnel as her engine uptakes were taken up through the lattice mainmast . The ship was fitted with two single 55 - caliber Škoda anti - aircraft guns , mounted on the forecastle and the stern . They had a maximum elevation of 85° and fired a shell at a muzzle velocity of . They had a rate of fire of 12 rounds per minute and had a maximum ceiling of . Four 67 - caliber Škoda AA guns were mounted between the bridge and the mainmast in a twin - gun mount on each side of the ship abreast the aircraft hold . They fired a shell at a muzzle velocity of . After her 1937 conversion to a minelayer , " Zmaj " carried 100 mines . A single disassembled de Havilland DH . 60 Moth floatplane was stored in the aircraft hold between the forward superstructure and the mainmast . Its components would be moved from the hold by the aircraft crane to the after deck where it could be assembled . Then the aircraft would be swayed over the side where it could be launched . Construction . " Zmaj " was built by Deutsche Werft in Hamburg , Germany . Due to the restrictions of the Versailles Treaty , she had to be built as an unarmed auxiliary . Her keel was laid down in 1928 and she was launched on 22 June 1929 . While en route to Yugoslavia she had a severe engine fire on 9 September 1929 off Flushing , Netherlands and was forced to return to Hamburg for repairs . These took almost a year and she was accepted by the Royal Yugoslav Navy on 20 August 1930 . She was finally commissioned in 1931 after she was armed and finished fitting - out in Kotor . Service . " Zmaj " appears to have been little used in her intended role ; only her salvage of an upside - down Dornier Wal in the Bay of Kotor in 1936 has been confirmed . This may be why she was converted to a minelayer the following year . Following her conversion she made port visits to Piraeus and Istanbul , accompanied by the destroyer " Dubrovnik " and the submarines and . " Zmaj " served as the fleet flagship in 1939 and witnessed the new destroyer run aground and sink in January 1940 at the narrow entrance to Sebenico harbor . Shortly before the German invasion of Yugoslavia on 6 April 1941 " Zmaj " laid defensive minefields along the Dalmatian Coast and off the main ports . These minefields may have caused the loss of the Yugoslav passenger ships SS " Karadjordje " and SS " Prestolonaslednik Petar " off Zlarin . " Zmaj " was captured in Split by the Germans on 17 April . Renamed as " Drache " ( " Dragon " ) by the Germans she was initially used in support of Luftwaffe seaplane units , but was redesignated as an aircraft rescue ship ( ) on 7 August 1941 . Her armament was increased by two and one anti - aircraft guns as well as racks for a dozen depth charge s . She was transferred on 27 December to the Aegean and reclassified as a troop transport . " Drache " was modified at Trieste between April and August 1942 for service as a minelayer . Her existing armament was replaced by two , five and six 2 cm AA guns . She was equipped with four mine rails on her after deck that could accommodate up to 120 mines and another 120 mines could be carried internally . Her crane was replaced by two derricks and the lattice mainmast was plated over and resembled a funnel . A platform was built behind the funnel above the main deck . " Drache " was recommissioned on 20 August 1942 and she was renamed " Schiff 50 " on 6 November . She conducted a number of minelaying operations in the Aegean as well as some of the west coast of Greece . After the surrender of Italy in September 1943 she was used to carry troops to reconquer the island of Kos on 2 – 3 October ( Operation Eisbär ) . On 8 October she was unsuccessfully attacked by the British submarine although her companion , the , was sunk . " Drache " s most successful operation was a mine barrage laid just east of the islands of Pserimos and Kalymnos to protect German troops during the Battle of Leros . The British destroyer and the , carrying supplies and reinforcements for the British forces on Leros , ran into this minefield on the evening of 22 October . " Adrias " had her bow blown off and " Hurworth " was sunk attempting to come to the aid of " Adrias " . " Adrias " , however , was eventually able to make it back to Alexandria . Two nights later the destroyer encountered the same minefield while carrying reinforcements to Leros . She hit a mine , broke in two , and sank in five minutes . " Drache " was also used for shipboard trials with the Flettner Fl 282 " Kolibri " ( Hummingbird ) helicopter . She embarked the V6 and V10 prototypes for a period in 1942 and in January – February 1943 . They used the small platform abaft the funnel to take - off and land . The German Navy ( ) wished to evaluate their potential for anti - submarine warfare and mine reconnaissance , but visual detection proved to be possible only in clear weather . The ship was attacked by Allied aircraft several times in 1943 and early 1944 , but she was only lightly damaged on two occasions . Nonetheless her anti - aircraft armament was augmented during 1944 . One quadruple 2 cm Flakvierling 38 mount was installed on each side of the bridge and she carried a total of thirteen 2 cm guns . Her 10 . 5 cm guns were exchanged for lighter guns to compensate for the increased top weight . However this proved to be insufficient to save " Drache " when she was attacked by several British Bristol Beaufighter s on the afternoon of 29 September 1944 while anchored in Vathy harbor on the Greek island of Samos . She was set on fire , exploded and sank two hours later ; eleven of her crew , including the commander Joachim Wünning , died during the attack . She was not salvaged and remained in place to be scrapped after the end of the war . See also . List of ships of the Yugoslav Royal Navy