On 27 August 1941, U-570 spent much of the morning submerged.
She had been four days at sea and this was to give respite to a crew that was suffering acutely from seasickness (several had been incapacitated).
Earlier that morning, a Lockheed Hudson bomber of 269 Squadron, RAF, flown by Sergeant Mitchell and operating from Kaldaðarnes, Iceland, had attacked her.
The attack failed when the Hudson's bomb-racks failed to release its depth charges.

U-570 surfaced at position 62°15′N 18°35′W at around 10:50 am, immediately below a second 269 Squadron Hudson, flown by Squadron Leader James Thompson.
Thompson was patrolling the area after Mitchell summoned him by radio.
Rahmlow, who had climbed out onto the bridge, heard the approaching Hudson's engines and ordered a crash-dive.
Thompson's aircraft reached U-570 before she was fully submerged and dropped its four 250-pound (110 kg) depth charges—one detonated just 10 yards (10 m) from the boat.

U-570 quickly resurfaced and around 10 of the crew emerged.
The Hudson fired on them with machine guns, but ceased when the U-boat crew displayed a white sheet.
The captured crewmembers later recounted to British naval intelligence interrogators what had happened—the depth charge explosions had almost rolled the boat over, knocked out all electrical power, smashed instruments, caused water leaks, and contaminated the air on the boat.
The inexperienced crew believed the contamination to be chlorine, caused by acid from leaking battery cells mixing with sea-water, and the engine-compartment crew panicked and fled forward to escape the gas.
Restoring electrical power—for the underwater electric motors and for lighting—would have been straightforward, yet there was nobody remaining in the engine compartment to do this.
The submarine was dead in the water and in darkness.
Rahmlow believed the chlorine would make it fatal to stay submerged so he resurfaced.
The sea was too rough for the crew to man their anti-aircraft gun so they displayed a white flag to forestall another, probably fatal, depth charge attack from the Hudson—they were unaware the aircraft had dropped all its depth charges.

Most of the crew remained on the deck of the submarine as Thompson circled above them, his aircraft now joined by a second Hudson that had been en route from Scotland to Iceland and had broken off its journey to lend assistance.
A radio request for help saw a Consolidated Catalina flying boat of 209 Squadron being scrambled at Reykjavík; it reached the scene three hours later.
The German crew radioed their situation to the German naval high-command, destroyed their radio, smashed their Enigma machine, and dumped its parts overboard along with the boat's secret papers.
Admiral Dönitz later noted in his war diary that he ordered U-boats in the area to go to U-570's assistance after receiving this report; U-82 responded, but Allied air patrols prevented U-82 from reaching U-570.

U-570's transmission was in plain language and the British intercepted it.
Admiral Percy Noble, commander of Western Approaches Command, immediately ordered several ships to race to the scene.
By early afternoon, fuel levels had forced the Hudsons to return to Iceland.
The Catalina, a very long-range aircraft, was ordered to watch the submarine until Allied ships arrived.
If none came before sunset, the aircraft was to warn U-570's crew to take to the water, then sink her.
The first vessel to reach U-570, the anti-submarine trawler HMT Northern Chief, arrived around 10pm, guided to the scene by flares the Catalina dropped.
The Catalina returned to Iceland after having circled U-570 for 13 hours.

The German crew remained on board U-570 overnight; they made no attempt to scuttle their boat as Northern Chief had signalled she would open fire and not rescue survivors from the water if they did this (Northern Chief's captain, N.L. Knight, had been ordered to prevent the submarine from being scuttled by any means.)
During the night, five more Allied vessels reached the scene: the armed trawler Kingston Agate, two anti-submarine whalers, the Ro
On 27 August 1941, U-570 spent much of the morning submerged. She had been four days at sea and this was to give respite to a crew that was suffering acutely from seasickness (several had been incapacitated). Earlier that morning, a Lockheed Hudson bomber of 269 Squadron, RAF, flown by Sergeant Mitchell and operating from Kaldaðarnes, Iceland, had attacked her. The attack failed when the Hudson's bomb-racks failed to release its depth charges.
U-570 surfaced at position 62°15′N 18°35′W at around 10:50 am, immediately below a second 269 Squadron Hudson, flown by Squadron Leader James Thompson. Thompson was patrolling the area after Mitchell summoned him by radio. Rahmlow, who had climbed out onto the bridge, heard the approaching Hudson's engines and ordered a crash-dive. Thompson's aircraft reached U-570 before she was fully submerged and dropped its four 250-pound (110 kg) depth charges—one detonated just 10 yards (10 m) from the boat.
U-570 quickly resurfaced and around 10 of the crew emerged. The Hudson fired on them with machine guns, but ceased when the U-boat crew displayed a white sheet. The captured crewmembers later recounted to British naval intelligence interrogators what had happened—the depth charge explosions had almost rolled the boat over, knocked out all electrical power, smashed instruments, caused water leaks, and contaminated the air on the boat. The inexperienced crew believed the contamination to be chlorine, caused by acid from leaking battery cells mixing with sea-water, and the engine-compartment crew panicked and fled forward to escape the gas. Restoring electrical power—for the underwater electric motors and for lighting—would have been straightforward, yet there was nobody remaining in the engine compartment to do this. The submarine was dead in the water and in darkness. Rahmlow believed the chlorine would make it fatal to stay submerged so he resurfaced. The sea was too rough for the crew to man their anti-aircraft gun so they displayed a white flag to forestall another, probably fatal, depth charge attack from the Hudson—they were unaware the aircraft had dropped all its depth charges.
Most of the crew remained on the deck of the submarine as Thompson circled above them, his aircraft now joined by a second Hudson that had been en route from Scotland to Iceland and had broken off its journey to lend assistance. A radio request for help saw a Consolidated Catalina flying boat of 209 Squadron being scrambled at Reykjavík; it reached the scene three hours later. The German crew radioed their situation to the German naval high-command, destroyed their radio, smashed their Enigma machine, and dumped its parts overboard along with the boat's secret papers. Admiral Dönitz later noted in his war diary that he ordered U-boats in the area to go to U-570's assistance after receiving this report; U-82 responded, but Allied air patrols prevented U-82 from reaching U-570.
U-570's transmission was in plain language and the British intercepted it. Admiral Percy Noble, commander of Western Approaches Command, immediately ordered several ships to race to the scene. By early afternoon, fuel levels had forced the Hudsons to return to Iceland. The Catalina, a very long-range aircraft, was ordered to watch the submarine until Allied ships arrived. If none came before sunset, the aircraft was to warn U-570's crew to take to the water, then sink her. The first vessel to reach U-570, the anti-submarine trawler HMT Northern Chief, arrived around 10pm, guided to the scene by flares the Catalina dropped. The Catalina returned to Iceland after having circled U-570 for 13 hours.
The German crew remained on board U-570 overnight; they made no attempt to scuttle their boat as Northern Chief had signalled she would open fire and not rescue survivors from the water if they did this (Northern Chief's captain, N.L. Knight, had been ordered to prevent the submarine from being scuttled by any means.) During the night, five more Allied vessels reached the scene: the armed trawler Kingston Agate, two anti-submarine whalers, the Ro
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