Access to the Atlantic was a coveted prize in the conquest of France and the Kriegsmarine quickly established naval bases at Brest, Lorient, St Nazaire, La Pallice and Bordeaux. This study examines how fortified U-boat bunkers and other facilities were constructed by the Todt Organization, assesses the level of French support in converting existing ports and describes the British campaign to thwart naval operations with aerial bombing and maritime attacks. Translated from the German by Geoffrey Brooks.