Were used primarily against Allied convoys in the Atlantic and Barents Sea. Was also used in the Arctic, Baltic Sea, Black Sea, Mediterranean, North Atlantic, and North Sea.
Used in support of U-Boats as far north as the Novaya Zemlya.
Used primarily from shore bases, but could also be used from seaplane tenders.
The Blohm und Voss Bv 138 started to be delivered to units at the end of 1940.
The Bv 138 performed long range reconnaissance, convoy patrol, mine sweeping, transport, and U-boat cooperation. The Bv 138 could stay in the air for 18 hours.
Often time the Bv 138 would land near a U-boat and take on diesel fuel from it to increase its range.