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.
History of the North Sea heightened in 1904 by the Dogger Bank incident. However, the British did not face a challenge to their dominance of the North Sea until World War I broke out in 1914. During the First World War the North Sea became the main theatre of the war for surface action. The Second World War also saw action in the North Sea, though it was restricted more to submarines and smaller vessels such as minesweepers, and torpedo boats and similar vessels. After the war, the North Sea lost much of its military significance because it is bordered only by NATO member-states. However,