Day 989 May 16, 1942

Gulf of Mexico. At midnight, U-507 sinks Honduran SS Amapala (1 killed, 56 survivors). At 11 AM off the Mississippi Delta, Louisiana, U-506 badly damages US tankers MV Sun and MV William C. McTarnahan. MV Sun reaches New Orleans for repairs under her own steam 14 hours later (all 48 hands survive). MV William C. McTarnahan (18 killed) is towed to Southwest Pass for repairs and 27 survivors on lifeboats and rafts are rescued by shrimp trawlers.

At 4.15 AM 200 miles East of the Bahamas, U-751 sinks American SS Nicarao, carrying 500 tons of fruit, bananas, coconuts and charcoal from Kingston, Jamaica, to Jacksonville, Florida (8 killed, 31 survivors picked up at midnight by US tanker Esso Augusta).

Kharkov offensive. Soviet 28th Army, the Northern pincer threatening Kharkov from the Volchansk salient, grinds to a standstill and goes over to the defensive. Southern pincer from the Izium salient continues to advance, with 6th Guards Cavalry Corps reaching the town of Krasnograd on the Berestovoy River. However, Soviet 21st and 23rd Tank Corps are still 15 miles behind the front and cannot reinforce the breakthrough. Meanwhile, German 1st Panzer Army prepares to counterattack and trap the Soviet troops in the giant Izium salient.

German cruiser Prinz Eugen sails from Trondheim, Norway, returning to Kiel, Germany, for repairs to torpedo damage from British submarine HMS Trident on February 23.

US submarine USS Tautog operates near the Japanese naval base at Truk to intercept Japanese ships returning from the Battle of the Coral Sea. USS Tautog torpedoes cargo ship Goyo Maru, which is beached.