 After her commissioning , Hamburg served with the fleet . She was assigned to I Subdivision of the Cruiser Division of the Active Fleet . The unit consisted of the light cruisers Frauenlob and Arcona and the armored cruiser Friedrich Carl , the flagship . The ships were attached to the I Squadron of the Active Fleet . A second subdivision , composed of an armored cruiser and three light cruisers was attached to the II Squadron . In April 1909 , Hamburg was cruising in the Mediterranean . On 21 April , she was dispatched from Corfu to Mersin , where rioting threatened German interests . She was joined there the following day by several British and French warships , including the battleship HMS Swiftsure . By 1912 , she was withdrawn from front @-@ line service for use as the second command flagship for the I U @-@ boat Flotilla . After the outbreak of World War I , she rejoined the fleet , but continued in her role as the I Flotilla flagship . On 6 August , she and the cruiser Stettin escorted a flotilla of U @-@ boats into the North Sea in an attempt to draw out the British fleet , which could then be attacked by the U @-@ boats . The force returned to port on 11 August , without having encountered any British warships . 
