In the Caribbean, 40 miles Southwest of Grenada, U-155 torpedoes Panamanian tanker SS Sylvan Arrow (1 killed, 43 survivors are picked up by US destroyer USS Barney and taken to Port of Spain, Trinidad). The captain and 11 crew return to salvage the wreck of SS Sylvan Arrow, which is taken in tow by a tug on May 26 but breaks up and sinks on May 28. The captain and 11 crew will be taken to Curaçao sent to USA on Dutch passenger steamer SS Crijnssen, but their adventure is only just beginning.
In the Gulf of Mexico, U-753 sinks American SS George Calvert on her maiden voyage 50 miles Northwest of Cuba and U-506 torpedoes US tanker SS Halo which explodes and sinks rapidly 50 miles South of Louisiana (19 killed immediately, 23 survivors drift for 5-7 days but only 3 ultimately survive).
Battle of Kharkov. German 6th Army and 1st Panzer Army continue closing the trap on Soviet forces in the Izium salient. 14th Panzer Division captures Protopopovka, narrowing the gap to only 12 miles. Soviet withdrawal out of the salient is hampered by the Luftwaffe. Ju88 bombers pummel retreating Soviet tanks and armoured columns, while Ju87 Stuka dive bombers destroy 5 bridges over the Donets River and damage 4 more to prevent Soviet forces escaping from the pocket.
In the North Atlantic 500 miles East of Bermuda, U-108 sinks Norwegian tanker MV Norland (all 48 hands escape in 3 lifeboats and survive) and U-158 sinks British tanker MV Darina (6 killed, 50 survivors rescued up to 6 days later), both dispersed from convoy ON-93. In the middle of the South Atlantic at 6.45 PM, German armed merchant cruiser Michel stops Norwegian SS Kattegat with shellfire. Michel sinks SS Kattegat after taking off all 32 crew, who suffer various ordeals as they are sent to Japan, France and back to Norway.
In the Mediterranean 10 miles off Sollum, Egypt, U-431 sinks British SS Eocene (all 35 crew, 6 gunners and 2 army engineers picked up by British anti-submarine whaler HMS Cocker and taken to Tobruk).