 The boat was commissioned into the Austro @-@ Hungarian Navy in September 1909 , and served as a training boat — sometimes making as many as ten cruises a month — through the beginning of the First World War in 1914 . At the start of that conflict , she was one of only four operational submarines in the Austro @-@ Hungarian Navy U @-@ boat fleet . Over the first year of the war , U @-@ 3 conducted reconnaissance cruises out of Cattaro . On 12 August 1915 , U @-@ 3 was damaged after an unsuccessful torpedo attack on an Italian armed merchant cruiser and , after she surfaced the next day , was sunk by a French destroyer . U @-@ 3 's commanding officer and 6 men died in the attack ; the 14 survivors were captured . 
 The boat was commissioned into the Austro @-@ Hungarian Navy in September 1909 , and served as a training boat — sometimes making as many as ten cruises a month — through the beginning of the First World War in 1914 . At the start of that conflict , she was one of only four operational submarines in the Austro @-@ Hungarian Navy U @-@ boat fleet . Over the first year of the war , U @-@ 3 conducted reconnaissance cruises out of Cattaro . On 12 August 1915 , U @-@ 3 was damaged after an unsuccessful torpedo attack on an Italian armed merchant cruiser and , after she<a href='been_done' title='1'><mark></mark></a> surfaced the next day , was sunk by a French destroyer . U @-@ 3 <a href='null_genetive' title='2'><mark>'s</mark></a>commanding officer and 6 men died in the attack ; the 14 survivors <a href='uninflect' title='3'><mark>were</mark></a> captured . 
Da boat was commissioned into the Austro @-@ Hungarian Navy in September 1909 , and served as a training boat — sometimes wit as many as ten cruises a month — through the beginning of tdaFirst World War in 1914 . At the start of that conflict , she was one of only four operational submarines in thdaustro @-@ Hungarian Navy U @-@ boat fleet . ova the first year of the war , U @-@ 3 conducted reconnaissance cruises out of Cattaro . On 12 August 1915 , U @-@ 3 was damaged after an unsuccessful torpedo attack on an Italian armed merchant cruiser and , after she done surfaced thedaxt day , was sunk by a French destroyer . U @-@ 3  commanding officer and 6 men died in the attack ; the dasurvivors was captured .