The struggle between the primacy of international law and military expediency lasted for nearly two years, as the British tried to reconcile their pre-war stance as champion of neutral rights with measures necessary for a successful blockade. Not until 1916 did the operation have the potential to be a decisive factor in the defeat of Germany, when pressure from France, the Royal Navy, Parliament, British popular opinion, and the Admiralty forced the British government to abandon its defence of neutral rights over the interests of the state.
The arrival of the United States as an ally in April 1917 initiated the final evolution of the blockade. The Entente and the United States tightened the blockade with crushing effect on Germany, and by November 1918, it was evidently one of the chief factors behind the victory. This knowledge reinforced the decision to retain the blockade in the months following the armistice in order to force favourable terms from Germany. In both the war and in the peace, the economic blockade performed a critical role in World War I.
There were those ships that went to war for the Kaiser on the high seas, those that stayed at home or otherwise played no significant part, and those that were commandeered (mostly in 1917 and by the United States) and used against Germany.
This is a well illustrated history, both practical and romantic, of the association each ship may have had with famous people and events of the war, and of the fates of the ships that comprised that fleet.