 Glasgow departed Coronel at 09 : 15 after having picked up the squadron 's mail and rendezvoused with the rest of the squadron four hours later . Cradock ordered his ships to form line abreast with an interval of 15 nautical miles ( 28 km ; 17 mi ) between ships to maximise visibility at 13 : 50 , and steered north at a speed of 10 knots ( 19 km / h ; 12 mph ) . At 16 : 17 Leipzig spotted Glasgow , the easternmost British ship , to its west and she spotted Leipzig 's funnel smoke three minutes later . At 17 : 10 Cradock ordered his ships to head for Glasgow , the closest ship to the Germans . Once gathered together , he formed them into line astern , with Good Hope in the lead , steering southeasterly at 16 knots ( 30 km / h ; 18 mph ) at 18 : 18 . As the sixteen 21 @-@ centimetre ( 8 @.@ 3 in ) guns aboard the armoured cruisers Scharnhorst and Gneisenau were only matched by the two 9 @.@ 2 @-@ inch guns on his flagship , he needed to close the range to bring his more numerous 6 @-@ inch guns to bear . The Force 7 winds and high seas , however , prevented the use of half of those guns as they were too close to the water . He also wanted to use the setting sun to his advantage so that its light would blind the German gunners . Spee was well aware of the British advantages and refused to allow Cradock to close the range . His ships were faster than the British , slowed by the 16 @-@ knot maximum speed of the armed merchant cruiser Otranto , and he opened up the range to 18 @,@ 000 yards ( 16 @,@ 000 m ) until conditions changed to suit him . The sun set at 18 : 50 , which silhouetted the British ships against the light sky while the German ships became indistinguishable from the shoreline behind them . 
