Patrol 04 - 11.03.1940-29.03.1940
11.03.1940 U-47 departs dock at Wilhelmshaven.
12.03.1940 U-47 receives fresh orders and proceeds at high speed towards Norway.
13.03.1940 U-47 receives a second change of orders and is assigned a new patrol area to the west.
??.03.1940 U-47, in the now more than familiar neighbourhood of the Orkneys, spots a Nelson class and two Queen Elizabeth class battleships. They are a few thousand yards too far away to attack.
25.03.1940 Steam freighter Britta (Denmark, 1,146 grt), attacked by torpedo, sunk. Time of first attack, 0540 hours. Location 60°00N/04°19W. This vessel, spotted at 0430 hours, is initially adjudged by Prien to be 3,000 tons. A single torpedo is fired, which misses. Prien thinks he has underestimated the ship's speed and size, and re-estimates the ship as being 5,000 tons. The second torpedo is more successful, and sinks the Britta.
??.03.1940 Late in the patrol U-47 receives an order to search for survivors of a downed Luftwaffe aircraft, but there is no sign of wreckage or a rubber dinghy.
29.03.1940 Following what proves to be a disappointing patrol, U-47 returns to dock at Wilhelmshaven.
Total days at sea: 19
Enemy vessels sunk: 1
Total tonnage: 1146 grt
Total days in port: 5