 At the same time , British submarines began reconnoitering the German patrol lines . On 23 August , several British commanders submitted a plan to attack the patrol line with the light cruisers and destroyers of the Harwich Force , commanded by Commodore Reginald Tyrwhitt . These ships would be supported by submarines and Vice Admiral David Beatty 's battlecruisers and associated light forces . The plan was approved and set for 28 August . The British forces began to leave port on the evening of 26 August , beginning with the submarines assigned to the operation . Most of the surface forces went to sea early on the following morning ; the 7th Cruiser Squadron , which had been added to provide further support to the Harwich Force , left port later in the day . 
