British CIC Middle East, General Wavell, is aware that Rommel’s Afrika Korps is receiving a full Panzer division to reinforce the under strength 5th Light Division. Worried about holding Tobruk and the Egyptian frontier due to the parlous state of his worn out armour, he appeals to London for more tanks particularly the fast but lightly armoured cruiser tanks. Churchill has always wanted to send tanks through the Mediterranean, so he redirects a convoy that is set to sail for Egypt via Cape of Good Hope, reducing the travel time from 50 days to 10 days (Operation Tiger). He adds an additional ship to carry 67 more cruiser tanks, realizing that “all may turn on a few hundred armoured vehicles” (total, 295 tanks).
In a speech, Irish Prime Minister Eamon De Valera protests German bombing of Belfast (in British Northern Ireland) saying “they are our people – we are one and the same people – and their sorrows in the present instance are also our sorrows”.
Greece. 100 Luftwaffe dive bombers attack Athens and Piraeus sinking Greek destroyer Psara (37 killed, 119 survivors) but they are engaged by 15 RAF Hurricanes (10 Hurricanes shot down, Germans lose 22 aircraft). Most Allied troops pass through Thermopylae, although the retreating column is still 10 miles long and under dive bomb attack. General Tsolakoglou takes unauthorized command of Greek Army of Epirus, which has been fighting the Italians in Albania, in order to surrender to the local German commander (Sepp Dietrich of Leibstandarte SS Adolf Hitler Regiment). This will be blocked by Mussolini who insists, with Hitler’s agreement, that Italy must take the Greek surrender.
At 3.32 AM 400 miles West of Ireland, U-73 sinks British SS Empire Endurance (previously German ship SS Alster, captured during the invasion of Norway) carrying supplies and 2 anti-submarine motor launches to Alexandria, Egypt, via the Cape of Good Hope. 64 crew members and 1 passenger are lost. 20 crew and 4 passengers are picked up on April 21 by Canadian corvette HMCS Trillium. 5 crew are picked up after 20 days by British passenger ship Highland Brigade.
British anti-submarine trawler HMT Topaze is accidentally rammed by British battleship HMS Rodney and sinks in the Clyde Estuary, Scotland (18 crew lost).