The Convoy System in the Mid-Atlantic, 1917–1918
When in February 1917 Germany started the unrestricted submarine campaign, the number of merchant ships sunken by U-boats increased, reaching its peak in April that year. From that time the number of vessels sunk started to decrease. However, a more detailed study of the number of ships sunk while navigating the area between the north Iberian peninsula and the Portuguese-held archipelagos of the Azores, Madeira and Cape Verde, shows a different reality. In this vast area, through which most of the Allied maritime traffic sailed, there was only a real decrease in ships sunk from May 1918. This article, using mainly primary English, German, French and Portuguese sources, shows this lesser-known reality and aims to give some possible explanations for this situation.