http://homepage.ntlworld.com/andrew.etherington/month/thismonth/31.htm
March 31st, 1940
UNITED KINGDOM: RAF Bomber Command: Reconnaissance of Germany.
RAF Fighter Command: Luftwaffe aircraft attacked the Orkneys, Shetland and shipping in the North Sea. aircraft driven off by fighters; 1 German aircraft severely damaged. No damage on land.
BATTLE OF THE ATLANTIC:
U-boats start withdrawing from the Western Approaches in preparation for the German invasion of Norway.
Losses. 2 ships of 11,000 tons.
1 U-boat.
Merchant Shipping War.
Losses. 43 ships of 96,000 tons.
ITALY: Mussolini warns King Victor Emmanuel III that Italy will join the war.
GERMANY: The German auxiliary cruiser Atlantis (ex SS Goldenfels), known to the Kriegsmarine as Schiff 16 and to the Royal Navy as Raider-C, sets off on a mission to catch and sink Allied merchant ships. Atlantis had been a merchant ship, but was converted to a commerce raider with six 5.9-inch (15 cm) guns, one 75 mm gun on the bow, and two twin-37 mm and four 20 mm automatic cannons all of which were hidden, mostly behind pivotable false deck structures. A phony crane and deckhouse on the aft section hid four of the 5.9-inch guns. The ship also had two waterline torpedo tubes, a 92 mine compartment, and two Heinkel He-114B seaplanes for reconnaissance. The Atlantis donned various disguises in order to integrate itself into any shipping milieu inconspicuously. Commanded by Kapitän zur See Bernhard Rogge, the Atlantis roamed the Atlantic and Indian oceans. She sank a total of 22 merchant ships (146,000 tons in all) and proved a terror to the British Royal Navy. (Jack McKillop)
FINLAND: In Soviet Union there is founded Socialist Karelo-Finnish Soviet Republic. Its territories include those recently conquered from Finland. The new republic’s leader is none else but Otto Wille Kuusinen, the Finnish emigrant communist and the recent Prime and Foreign Minister of the so-called Finnish People’s Government. In Finland this move is seen as yet another evidence that Stalin prepares to annex the rest of Finland at the first opportunity. (Mikko Härmeinen)
http://worldwar2daybyday.blogspot.com/
Day 213 March 31, 1940
Following French backtracking on mining the River Rhine (due to their fear of German reprisal bombings), British Prime Minister Neville Chamberlain calls off mining the Norwegian coast planned for April 5. Chamberlain tells the French ambassador in London Charles Corbin “No mines, no Narvik!” This act of bravado leads to a delay which will prove to be costly.
German armed merchant cruisers (Hilfskreuzer) Atlantis, Orion and Widder depart from Kiel, with WWI battleship SMS Hessen acting as an icebreaker, for operations against Allied shipping. Atlantis will prove the most successful German commerce raider, sailing 100,000 miles and sinking 22 ships (over 140,000 tons) in a voyage lasting 602 days (until November 22, 1941). http://www.bismarck-class.dk/hilfskreuzer/atlantis.html
Oberleutnant zur See Hans-Wilhelm Behrens falls overboard from U-43 and drowns in the Atlantic.