The Austro-Hungarian Navy's U-boat fleet at the beginning of World War I consisted of six largely experimental submarines, two of which were not operational.

[3][Note 3] The first contract in February 1915 secured the purchase of U-10 and U-11, initially commissioned as the German Type UB I U-boats UB-1 and UB-15, respectively.

All five were transported by rail in sections to the navy yard at Pola, where they only needed riveting together to be complete,[1] a process that typically took about two weeks.

[5][6] The other three ships were never manned by German crews and had all been commissioned by early October when each is listed in sources with a commanding officer.

[7] On a single day, 25 June 1916, U-15 sank the Italian auxiliary cruiser Citta di Messina and the French destroyer Fourche in the Strait of Otranto,[14] accounting for almost half of her wartime successes.

Although she was looted by Austro-Hungarian Army troops, she was later towed to Trieste for repairs which remained incomplete at the war's end.

After the end of fighting in November 1918, the four surviving class members—U-10, U-11, U-15, and U-17—were all turned over to Italy as war reparations and scrapped at Pola by 1920.

She was laid down on 9 November 1914 in Germany and shipped by rail to Pola where she was assembled, launched, and commissioned as SM UB-15 on 11 April 1915.

SM U-15 was constructed in Germany and shipped by rail to Pola where she was assembled and launched in September 1915 and commissioned on 6 October.

SM U-16 was constructed in Germany and shipped by rail to Pola where she was assembled and launched on 26 April 1915 and commissioned on 6 October.

While operating in the Adriatic off the coast of Albania in mid-October 1916, U-16 sank an Italian destroyer acting as a convoy escort.

SM U-17 was constructed in Germany and shipped by rail to Pola where she was assembled and launched on 21 April 1915 and commissioned on 6 October.