ulf ▁of ▁R iga , ▁Ost f ries land ▁and ▁her ▁three ▁sister s ▁were ▁moved ▁to ▁the ▁Dan ish ▁stra its ▁to ▁block ▁any ▁possible ▁British ▁attempt ▁to ▁interven e . ▁On ▁ 2 8 ▁October ▁the ▁four ▁ships ▁arrived ▁in ▁P utz ig ▁W iek , ▁and ▁from ▁there ▁ste amed ▁to ▁Ar ens burg ▁on ▁the ▁ 2 9 th . ▁On ▁ 2 ▁November ▁the ▁operation ▁was ▁completed ▁and ▁Ost f ries land ▁and ▁her ▁sister s ▁began ▁the ▁voyage ▁back ▁to ▁the ▁North ▁Sea . ▁In ▁March ▁ 1 9 1 8 , ▁N atz mer ▁was ▁replaced ▁as ▁the ▁ship ' s ▁commander ▁by ▁K z S ▁Hans ▁Herr . ▁A ▁final ▁abort ive ▁fleet ▁sortie ▁took ▁place ▁on ▁ 2 3 – 2 4 ▁April ▁ 1 9 1 8 . ▁Ost f ries land , ▁Th ür ingen , ▁and ▁N ass au ▁were ▁formed ▁into ▁a ▁special ▁unit ▁for ▁Operation ▁Schl uß stein , ▁a ▁planned ▁occupation ▁of ▁St . ▁Petersburg . ▁The ▁three ▁ships ▁reached ▁the ▁Balt ic ▁on ▁ 1 0 ▁August , ▁but ▁the ▁operation ▁was ▁post pon ed ▁and ▁eventually ▁can ce led . ▁The ▁special ▁unit ▁was ▁dissol ved ▁on ▁ 2 1 ▁August ▁and ▁the ▁batt les hips ▁were ▁back ▁in ▁Wilhelm sh aven ▁on ▁the ▁ 2 3 rd . ▁ ▁The ▁end ▁of ▁the ▁war ▁ ▁Ost f ries land ▁and ▁her ▁three ▁sister s ▁were ▁to ▁have ▁taken ▁part ▁in ▁a ▁final ▁fleet ▁action ▁at