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.
UB-148 at sea, a U-boat similar to UB-91.
Deck gun in Chepstow today
German Type UB III submarine
The Type UB III submarine was a class of U-boat built during World War I by the German Imperial Navy.
UB-86 washed ashore 1921
Image: German Type UB III submarine model 1
Image: German Type UB III submarine model 3