At the start of World War I, "Helgoland" was assigned to I Division, I Battle Squadron. "Helgoland" was stationed off the heavily fortified island of Wangerooge on 9 August. Minefields and picket lines of cruisers, torpedo boats, and submarines were also emplaced there to defend Wilhelmshaven. "Helgoland"s engines were kept running for the entirety of her deployment, so that she would be ready to respond at a moment's notice. Four days later, on 13 August, "Helgoland" returned to Wilhelmshaven to refuel. The following day, naval reservists began arriving to fill out the wartime complements for the German battleships.