The US response to the U-boat threat on the East Coast was now stepping up a gear, with many small patrol boats joining the hunt. U-333 had been lucky to escape on the 7th, now U-352 was subjected to a thorough hunt.

On 9th May the 165 foot US Coast Guard Cutter Icarus was cruising at 14 knots in a calm sea off North Carolina when she picked up something on her sound equipment. The Division of Naval Intelligence

Icarus' sound equipment indicated on initial contact that a possible submarine was an estimated 100 yards ahead. Nothing was in sight. Four minutes later a torpedo was seen to explode approximately 200 yards off port quarter. The captain of the Icarus immediately reversed course. Reaching the eastern edge of the whirl caused by the torpedo explosion, he laid a diamond pattern of five depth charges. He then circled the spot and dropped three more depth charges in a "V" pattern.

Large air bubbles were observed on the surface. Icarus dropped another depth charge. A minute later, at 1709 E. D. T., the U-boat broke the surface at a 45° angle, down by the stern.

Icarus immediately opened fire with her 50-caliber machine gun on her starboard quarter and 30-caliber machine gun on the flying bridge. By that time she had moved to approximately 1,000 yards distance. Men were seen climbing from the U-boat's conning tower.

Icarus swung around as quickly as possible to bring her 3-inch gun to bear. Her first two shells straddled the U-boat, then the gunner found the target. Out of 14 shots 6 direct hits and 1 ricochet hit were scored on the hull and conning tower. Thirty-three men tumbled from the conning tower in clocklike precision, swimming rapidly away from the boat. U-352 remained on the surface 5 minutes. She sank at 1714 and Icarus, now 300 yards away, ceased firing.

Icarus, circled the spot. At about 300 yards from the survivors she picked up another contact. She proceeded to the indicated area and dropped another depth charge at 1734. A large amount of oil came to the surface, described as a light Diesel oil, practically colorless, with a strong odor like kerosene.

‘Prisoners stated that they heard a hail of depth charges, some of them extremely close. The first explosions destroyed the periscope and killed an officer in the conning tower. Gauges and glasses were smashed in the control room.’

The commanding officer of Icarus dispatched a message requesting instructions how to proceed from this point. Upon receipt of orders, he picked up 33 survivors at 1750 and proceeded to Charleston, S.C.

Meanwhile, what was happening inside the U-boat? The full account remains concealed behind the crew's reticence. The following story, however, can be pieced together from available information:

One prisoner stated that U-352 had been in the area of her final battle for about 4 days.

When U-352 sighted Icarus she was dead ahead. "Action stations" was sounded. Rathke manoeuvered into position at periscope depth and fired one bow torpedo, believed to have been electric. There is reason to believe that Rathke mistook Icarus for a larger craft. The U-boat crew heard an explosion. Some, at least, thought momentarily that they had scored a hit. If Rathke thought so he could not have been long deceived. In reality, the torpedo broached, sank and exploded, churning mud to the surface.

Rathke believed he was operating in water 95 feet deep. (Actually it was nearer 120 feet). Apparently hoping to avoid Icarus' antisubmarine devices, he took his boat to the approximate position of the torpedo explosion and there grounded her. Ironically, this was precisely the spot Icarus chose for her first depth charge attack.

Prisoners stated that they heard a hail of depth charges, some of them extremely close. The first explosions destroyed the periscope and killed an officer in the conning tower. Gauges and glasses were smashed in the control room. The deck was littered with broken gear. Lockers burst open. Crockery and other loose objects were flung about the boat. The crew was shaken up. All lights except the emergency system failed. There is evidence that the electric motors failed - perhaps the greatest injury the boat suffered. There apparently was no water or chlorine gas in the boat.

Rathke seems to have concluded that his craft was damaged beyond hope of saving. He stated later he believed about 60 depth charges had been dropped. Rathke ordered his men to put on lungs and lifejackets. He blew the tanks and gave the command to abandon ship.

The crew of U-352 had been in St Nazaire when the British launched their Commando raid which put the port out of action for large ships. Interrogation of the prisoners might have provided valuable intelligence on the results of the raid.

However, after a copy book attack the US Navy and Coast Guard still had some lessons to learn in the handling of prisoners. The U-Boat officers were allowed to exercise control over their men even after they landed. As a consequence they retained their discipline and were tight lipped when interrogated - one man even admitted that he thought he would be shot after the war if he told them anything.

The commander of U-352 Kapitänleutnant Hellmut Rathke was a committed Nazi:

Rathke spoke of Hitler as a "genius" who has unified all the German peoples of Europe. He said Hitler likes the navy, and makes frequent trips in cruisers to the Norwegian fjords.

On such cruises Hitler dines in the wardroom. He listens attentively to the conversation and may call upon someone at the other end of the table to verify a statement which he has heard. Rathke said Hitler has an amazing knowledge of detail, not only of things naval, but in all fields. Rathke said Hitler was not only a military genius but "a genius in everything."