sm "ub-46" was commissioned into the german imperial navy on 12 june 1916 under the command of oberleutnant zur see cäsar bauer. "ub-46", bauer's third u-boat command, was assigned to the navy's pola flotilla (). although the flotilla was based in pola, the site of the main austro-hungarian navy base, boats of the flotilla operated out of the austro-hungarian base at cattaro which was located farther south and closer to the mediterranean. german u-boats typically returned to pola only for repairs. after a month at the helm of "ub-46", bauer was promoted to kapitänleutnant.