On 18 August , the Germans again sortied , this time to bombard Sunderland ; Scheer hoped to draw out Beatty 's battlecruisers and destroy them . British signals intelligence decrypted German wireless transmissions , allowing Jellicoe enough time to deploy the Grand Fleet in an attempt to engage in a decisive battle . Both sides withdrew the following day , after their opponents ' submarines inflicted losses in the Action of 19 August : the British cruisers Nottingham and Falmouth was both torpedoed and sunk by German U @-@ boats and the German battleship SMS Westfalen was damaged by the British submarine E23 . After returning to port , Jellicoe issued an order that prohibited risking the fleet in the southern half of the North Sea due to the overwhelming risk from mines and U @-@ boats .