 The ship participated in combined fleet maneuvers between Provence and Tunisia in May–June 1913 and the subsequent naval review conducted by the President of France, Raymond Poincaré on 7 June 1913.Afterwards, "Diderot" joined her squadron in its tour of the Eastern Mediterranean in October–December 1913 and participated in the grand fleet exercise in the Mediterranean in May 1914.In early August 1914, the ship cruised the Strait of Sicily in an attempt to prevent the German battlecruiser and the light cruiser from breaking out to the West.