After another hour, it was completely dawn, and the snow-capped Canadian coast was clearly in sight.

The U-400 was about 13 meters underwater, and still unhurriedly headed to the southern tip of Newfoundland at a speed of about 10 knots, dragging two inconspicuous white tracks behind it.

At this time, the United States and Canada had already deployed some antisubmarine patrol planes in the coastal areas, and Admiral Dönitz had withdrawn his submarine forces from the east coast and the Caribbean region of the United States because the US antisubmarine patrol planes had suppressed submarines very strongly, and these US antisubmarine bombers equipped with radars could be on duty day and night over the coast, and the sea-detection radars equipped with the planes could detect submarines that had surfaced more than 30 nautical miles.

The latest UX.XI./41D ocean-going attack submarines, equipped with underwater snorkels, do not need to surface regularly to recharge their batteries and exchange fresh air for their interiors, as was the case with previous submarines. Theoretically, submarines of this class are quite capable of staying underwater for long periods of time.

Still, at night, Haldegen would order submarines to surface to carry out an important technical test by the Navy's technical department: whether the German Navy's latest passive radar receivers could detect enemy patrol planes before they could detect them.

This is an extremely dangerous job, and if these aircraft are not effective, the submarine runs the risk of being attacked by enemy aircraft. Fortunately, the latest Gema41 new detection radar equipped on German submarines has greatly improved its efficiency due to the introduction of the latest magnetron technology from the Austro-Hungarian military, and it can detect surface ships 20 nautical miles away and air targets 45 nautical miles away, which is another important guarantee for the safety of submarines.

On the night of December 2, the U-400 successfully evaded two waves of enemy anti-submarine patrol planes using a new type of passive radar. And during the day on December 3, four groups of enemy anti-submarine aircraft were spotted flying overhead. Obviously, the airborne radars of the United States and Britain are not yet able to penetrate the sea water at a depth of more than 10 meters and discover submarines that are diving under the surface.

Still, there was an enemy patrol aircraft hovering overhead for a while. Haldegen did not order the submarine to dive to evade, but only ordered the submarine to slow down, and in this way engaged in a maneuver with the enemy plane for more than ten minutes. He knew that scientists had developed a magnetic anomaly detection device capable of detecting submarines underwater, and it was estimated that the enemy plane might have been equipped with something similar.

This was a new situation, and after the departure of the enemy aircraft, Major Haldegen immediately reported this situation and his own speculation to the submarine command.

Shortly before noon on 3 December, the 101st Submarine Squadron sailed slowly south along the coast of Newfoundland, approaching the entrance to Cabot Strait. A small cargo ship of about a thousand tons or so was discovered. The cargo ship was exactly within the range of the U-400, and Major Haldegen thought about it through the periscope and gave up the "prey". If an attack were launched at this time, it could cause a distress signal, which would lead the enemy to conduct a comprehensive sea and air search for the submarine near the Cabot Strait, which would not be conducive to the next operation of the entire squadron. If the British were not alarmed now, it would be easier to achieve greater results by diving into the southern shipping channel after dark.

Major Haldegen intends to make a big deal here. Then slip straight away and head straight to the East Coast of the United States.

After maneuvering with enemy patrol aircraft. The excellent performance of the new submarine made him even more confident.

Haldegen ordered the formation to continue southward through the American shipping route to the Gulf of St. Lawrence, and then set up an ambush in the area.

The 101st Submarine Squadron waited for the first "prey" to enter the ambush circle just before dawn, and the officer on duty reported that the radar had spotted a convoy of three large merchant ships heading out of the Bay of St. Lawrence towards the shores of the United States. It was close to 6:15 a.m. and the sky was getting brighter. After a while. Hadelgen saw through the periscope a sight that all submarine commanders coveted: three merchant ships of about 10,000 tons lined up in a column, smoothly approaching their ambush site on the sea, without the escort of warships.

Inside the U-400, the crew was ready for battle, and the killing machine had already shown its sharp teeth. Through the thin hull. The crew could hear the louder and louder ping-pong sounds coming from the sonar room, the sound was sharp and quivering. The echo detector emits a higher pitch than usual when capturing multiple targets, fluttering more violently, with a special timbre.

"Esther, let's attack the target at the end of the fleet first!" Hadergen said to the gunner, who was operating another periscope.

"Yes, sir! One last goal! The gunnery replied loudly.

Major Hadergen saw three hazy gray shadows appear in the dark sea from the periscope, and since it was not yet dark, the navigation lights on the ship were still on, which made them easier to expose. Ships in Europe would never dare to sail with their navigation lights on so swaggeringly, and it is clear that the Americans and Canadians in North America have not yet developed such good habits, and they have not adopted light control.

Now several ships are about 12,000 meters away from the U-400 and are actually within torpedo range. But the vast majority of German submarine commanders did not attack at this distance, and in fact, the probability of a torpedo hitting a target at a distance of more than 3000 meters was quite low.

German submarine commanders preferred to use high-speed attacks at close range when attacking merchant ships without escort, so that the hit rate would reach about fifty percent. Although it is still a little far away, Hadergen can still judge that it is a 10,000-ton oil tanker and two standard ocean-going freighters of 8,177 tons built in batches during the war.

This type of ship is most common in the United States and the United Kingdom, but it is not necessarily an American or British ship, but it may also be a ship belonging to a neutral country. But the Axis powers had declared unrestricted submarine warfare, and all ships entering the territorial waters of the United States, Britain, Soviet Russia, and Japan would be attacked as "enemy ships," so German submarine commanders had no trouble identifying the flags flying on ships.

"6200 meters, the front torpedo compartment is ready, the maneuver angle is 3, and the depth is 3 meters!" For the first time, Lieutenant Esther gave the order to the torpedo compartment to prepare for launch.

Two minutes later, he reported to Major Hadelgen: "Ready for launch, sir! ”

"Well, keep the current course, a third of the speed!" Hadergen said he needed to wait for the two ships in front of him to sail by. The U-400 was armed with six bow torpedo tubes and two stern torpedo tubes, carrying a total of 24 torpedoes. When attacking unprotected merchant ships, generally 2-3 torpedoes are enough.

Perhaps because they had not been attacked by submarines for a long time and were close to the Canadian coast, the three freighters did not make a single anti-submarine maneuver, but sailed straight along the channel, which allowed the lurking German submarines to lock on to the target with ease, and the sailors on this steamer seemed unable to see the "wolves" lurking in the dark water 2,000 meters away from them, and the waves on the sea made it impossible for them to distinguish the two periscopes and the submarine antenna about 1.5 meters above the water.

"Three attacks, start!" After about half an hour of lurking, Hadelgen finally gave the order to attack.

"Launch One! …… Launch Two! …… Launch Three! ”

The submarine shook and made a wave as usual, and three torpedoes were fired from the bow of the U-400. (To be continued......)