SM UB-91 [SEP] vessel class
SM UB-91
SM "UB-91" was a German Type UB III submarine or U-boat in the German Imperial Navy () during World War I. She was commissioned into the German Imperial Navy on 11 April 1918 as SM "UB-91".
On 4 October 1918 "UB-91" sank the , killing among others, Yokohama Specie Bank sub-manager S. Ujie, his wife and three sons, together with bank employee Takashi Aoki and wife Sueko.
Surrender.
"UB-91" was surrendered to Britain on 21
with a deck-mounted machine gun. "UB-13" was broken into sections and shipped by rail to Antwerp for reassembly. She was launched in March 1915 and commissioned as SM "UB-13" in April.
"UB-13" spent her entire career in the Flanders Flotilla and sank 11 merchant ships, about half of them British fishing vessels. In March 1916, "UB-13" was responsible for sinking the Dutch ocean liner , raising the ire of the Dutch public. "Tubantia" was the largest neutral vessel sunk during