 The Germans sortied from Messina on 6 August and headed east , towards Constantinople , trailed by Gloucester . Milne , still expecting Rear Admiral Wilhelm Souchon to turn west , kept the battlecruisers at Malta until shortly after midnight on 8 August , when he set sail for Cape Matapan , where Goeben had been spotted eight hours earlier , at a leisurely 12 knots ( 22 km / h ) . At 2 : 30 p.m. he received an incorrect signal from the Admiralty stating that Britain was at war with Austria — war would not be declared until 12 August and the order was countermanded four hours later , but Milne followed his standing orders to guard the Adriatic against an Austrian breakout attempt , rather than seek Goeben . Finally on 9 August Milne was given clear orders to " chase Goeben which had passed Cape Matapan on the 7th steering north @-@ east . " Milne still did not believe that Souchon was heading for the Dardanelles , and so he resolved to guard the exit from the Aegean , unaware that the Goeben did not intend to come out . 
