Using information from Ultra intercepts, Royal Navy hunts the network of German supply ships that refuel surface raiders and U-boats in the Atlantic. 80 miles Southwest of Greenland, cruisers HMS Aurora and HMS Kenya attack German tanker Belchen while refueling U-93. U-93 crash dives. Belchen is hit with shellfire and a torpedo from HMS Aurora and then finally scuttled by her crew (5 killed). British ships leave without picking up survivors, knowing there is a U-boat nearby, but 50 crew are rescued later in the day by U-93.
950 miles West of Brest, France, U-48 and U-75 attack convoy OB-327 sinking Dutch MV Eibergen (4 dead, 35 survivors picked up by a British anti-aircraft ship HMS Cairo on June 7) and British tanker Inversuir (all 45 hands rescued by Norwegian steam merchant Para, destroyer HMS Wanderer and an unknown vessel).
British liner SS Mamari (used by Royal Navy as Fleet Tender C, a decoy version of the aircraft carrier HMS Hermes) is attacked by German aircraft off the English coast near Cromer, Norfolk. Mamari takes evasive action and becomes stuck on the submerged wreck of steam tanker Ahamo (sunk on a mine on April 8). The crew is taken off by rescue tug Sabine. Overnight, Mamari is torpedoed by German E-boats before she can be salvaged.