 The MGB @-@ 314 replied in a coded response obtained from a German trawler boarded during the <unk> raid . A few bursts were fired from a shore battery and both Campbeltown and MGB @-@ 314 replied : " Ship being fired upon by friendly forces " . The deception gave them a little more time before every German gun in the bay opened fire . At 01 : 28 , with the convoy 1 mile ( 1 @.@ 6 km ) from the dock gates , Beattie ordered the German flag lowered and the White Ensign raised . The intensity of the German fire seemed to increase . The guard ship opened fire and was quickly <unk> when the ships in the convoy responded , shooting into her as they passed . 
