Submarines for the Austrian navy according to the Dutch magazine Marineblad dated 1909-1910 no. 8

An item reported that the intention was to start that year with the building by Whitehead of the submarines U7-U8 of the Holland-design, the U9-10 at Kiel and U11-12 in the arsenal of Pola with as result a future increase of the number of submarines from 6 to 12.