Isle of Man Steam Packet Company England, Wales, Scotland and Ireland. Ports served included Liverpool, Silloth, Whitehaven, Holyhead, Ardrossan, Blackpool, Belfast and Dublin. Vessels and crews of the company were actively involved in both the First and Second World Wars. One vessel, , was attached to the British Grand Fleet and led the German High Seas Fleet into Scapa Flow in the Orkney Islands at the end of the First World War. Another vessel, "Viking", was converted to become a seaplane carrier, serving as . During the First World War, eleven out of a total fleet of fifteen Steam Packet ships were requisitioned by the Admiralty.
Romanian Black Sea Fleet during World War I machine guns. The minelayer "Alexandru cel Bun" was armed with two 37 mm guns and two machine guns, in addition to her load of mines. The main Romanian port of Constanța was leased to a Russian naval squadron, headed by the battleship "Rostislav". This, combined with the fall of the port to the Central Powers during the Second Battle of Cobadin, rendered the small Northern port of Sulina as the base for the Romanian Black Sea Fleet. On 13 November 1916, the German minelaying submarine "UC-15" set off to lay mines off Sulina. However, she only managed to lay two