She spent most of the rest of the year searching for German commerce raiders and escorting convoys before she became flagship of the 1st Cruiser Squadron.

In early 1915, she was reassigned to the 6th Cruiser Squadron before she became flagship of the North America and West Indies Station, based at the Royal Naval Dockyard in the Imperial fortress colony of Bermuda, in March.

Leviathan retained that position for the next three years until she was relieved as flagship in early 1918 and began escorting convoys from North America to Britain.

She was powered by two 4-cylinder triple-expansion steam engines, each driving one shaft, which produced a total of 30,000 indicated horsepower (22,000 kW) and gave a maximum speed of 23 knots (43 km/h; 26 mph).

[1] Leviathan, named after the Biblical sea monster,[8] was laid down by John Brown and Company at their shipyard in Clydebank on 30 November 1899.

[9] The ship sailed to Portsmouth for armament and engine tests in March 1902,[10] and was completed on 16 June 1903 when she was initially assigned to the China Station.

On 2 December, she was in Cromarty Firth and hoisted the flag of Rear Admiral Archibald Moore, commander of the 1st Cruiser Squadron.

Moore struck his flag on 17 January 1915 and transferred to the battlecruiser New Zealand at Rosyth[12] and the ship rejoined the 6th Cruiser Squadron.

On 9 March, she was unsuccessfully attacked by the German submarine U-12 whilst en route to Rosyth to pick up Vice Admiral George Patey, the new Commander-in-Chief, North America and West Indies Station.