 Because of her limited range , UB @-@ 7 would not have been able to make the entire journey to Turkey , so on the night on 15 / 16 May , she was towed by the Austrian destroyer SMS Triglav through the Straits of Otranto and into the Ionian Sea . By June , UB @-@ 7 had reached Smyrna — not having any success on her journey there — and joined U @-@ 21 and UB @-@ 8 in the Constantinople Flotilla ( German : U @-@ boote der Mittelmeer division in Konstantinopel ) . Once there , UB @-@ 7 was ineffective because she was hampered by her limited torpedo supply and her weak engines , which made negotiating the strong Dardanelles currents nearly impossible . Because of this , UB @-@ 7 was sent to patrol in the Black Sea in July , cruising without success from the 5th to the 22nd . 
