 On 7 – 10 March 1915 , the Grand Fleet conducted a sweep in the northern North Sea , during which it undertook training manoeuvres . Another such cruise took place during 16 – 19 March . On 11 April , the Grand Fleet conducted a patrol in the central North Sea and returned to port on 14 April ; another patrol in the area took place during 17 – 19 April , followed by gunnery drills off the <unk> on 20 – 21 April . The Grand Fleet conducted a sweep into the central North Sea during 17 – 19 May without encountering German vessels . Another patrol followed during 29 – 31 May ; it too was uneventful . The fleet conducted gunnery training in mid @-@ June . During 2 – 5 September , the fleet went on another cruise in the northern end of the North Sea and conducted gunnery drills . Throughout the rest of the month , the Grand Fleet conducted numerous training exercises . 
