Over the Type UB Is ' first year of service , UB @-@ 4 and UB @-@ 13 were both lost , and UB @-@ 2 and UB @-@ 5 were transferred to the Baltic Flotilla . In March 1917 , UB @-@ 6 ran aground in Dutch waters and was interned for the rest of the war , along with her crew . The four remaining Type UB Is in Flanders — UB @-@ 10 , UB @-@ 12 , UB @-@ 16 , UB @-@ 17 — were all converted to minelayers by 1918 , having their torpedo tubes removed and replaced with chutes to carry up to eight mines . All but UB @-@ 10 were lost in 1918 ; UB @-@ 10 , in poor repair and out of service , was scuttled in October 1918 when the Germans evacuated from Flanders .