The "Kriegsmarine" participated in the Battle of Westerplatte and the Battle of the Danzig Bay during the invasion of Poland. In 1939, major events for the "Kriegsmarine" were the sinking of the British aircraft carrier and the British battleship and the loss of the at the Battle of the River Plate. Submarine attacks on Britain's vital maritime supply routes (Battle of the Atlantic) started immediately at the outbreak of war, although they were hampered by the lack of well placed ports from which to operate. Throughout the war the "Kriegsmarine" was responsible for coastal artillery protecting major ports and important coastal areas. It also operated anti-aircraft batteries protecting major ports.