 Soon after she left Pola , UB @-@ 50 encountered the William H. Crawford , a 1 @,@ 593 GRT American sailing ship . It sank after an attack from the U @-@ boat stopped her . Four days later , UB @-@ 50 sighted the 800 GRT British barge <unk> UB 50 launched a torpedo which instead hit the British tug towing the ship , the 121 GRT <unk> The tug sank , but the barge was not sunk . The following day , UB @-@ 50 found two Portuguese sailboats <unk> De <unk> and <unk> Da <unk> at 30 GRT and 32 GRT respectively . They were sunk 6 nautical miles ( 11 km ; 6 @.@ 9 mi ) north of Cape <unk> . A day later , she found the Portuguese 233 GRT ship Sado , which she sank about 16 nautical miles ( 30 km ; 18 mi ) south of her prey the day before . Four days later , UB @-@ 50 finally encountered and sank a merchant , this being the 3 @,@ 611 GRT British Polar Prince , carrying coal for Malta . Two days later , she sank the Fabian , a 2 @,@ 246 GRT British steamer going to Liverpool , killing three . Later that day , she sank the <unk> <unk> , a 4 @,@ 124 GRT ton Italian steamer carrying ore . The 2 @,@ 464 GRT coal carrying Greek steamer <unk> was attacked two days later by UB @-@ 50 , sinking close off Oran . The UB 50 followed up with the sinking of the 1 @,@ 670 GRT Norwegian steamer John Knudsen , killing one . Four days later , the 296 GRT Italian sailboat Ciro was scuttled after being hit by UB @-@ 50 , the last ship she would sink before returning to base . 
