Although the reputation of the German submarine force was intimidating to the Anglo-American alliance, the Austro-Hungarian Navy had already caught up with their German counterparts in submarine technology during the First World War. By World War II, the Austro-Hungarian Navy was even slightly ahead of their allies in many submarine technologies, and with their support, the Chinese Navy had made great strides in submarine construction.

In the early days of the Sino-Japanese War, the surface ship forces of the Chinese Navy were completely suppressed by the Japanese Navy, and it was almost impossible to go to sea to fight, relying only on a dozen old submarines to deal with the Japanese. But as the war progressed, especially after the four shipyards in Qinzhou, Beihai, Tianjin and Qingdao were renovated and expanded, the Chinese Navy began to manufacture submarines in batches, and almost every month three or four new submarines were launched into service.

So far, with the assistance of Germany, Austria and Italy, the Chinese Navy has been equipped with more than 150 submarines, making it an underwater force to be reckoned with. Due to the limitations of industrial technology, although the Chinese-made submarines cannot dive to the "extreme depth" of more than 200 meters like the German-Austrian submarines, they are still quite comfortable in dealing with the Japanese, who have only one antisubmarine means and backward technology.

Throughout the Ryukyu Campaign, more than 120 Chinese submarines and more than 50 German-Austrian submarines were operating around Japan, not only sabotaging and blockading Japan's already weak sea transportation, but also tasked with monitoring and attacking the Japanese fleet.

"Sir, we've arrived at the designated 31st Sea Zone!" Since the loss of the traces of Ozawa's fleet in the Osumi Strait the night before yesterday, the Chinese 12th Submarine Group, which has been in charge of monitoring the whereabouts of Ozawa's fleet, has been tracking the whereabouts of enemy ships, and at the same time, more than 20 submarines of the Chinese 9th Submarine Group and the 3rd Austro-Hungarian Far East Submarine Group, which are deployed in the waters east of the Ryukyus, have also been dispatched to the Kyushu Sea and the northern part of the Philippine Sea basin to carry out search missions.

Ever since the submarine departed from the predetermined sea area, the navigator on board has been calculating the navigation chart according to the submarine's course, speed and time, as long as the distance is not too far and the sea conditions are acceptable. The error of this calculation is essentially negligible.

"One-third of the speed forward!" In the command cabin of submarine No. 1201, the lieutenant colonel commander sitting in front of the periscope shouted into the microphone leading to the engine room, and then shouted to the sonar room: "Sonar closely monitors the sea situation!" After giving the order, he pressed his eyes to the observation eyepiece, slowly turned the periscope handle, and continued to search the sea.

But there is nothing noteworthy on the sea. After two rounds of searching, Lieutenant Colonel Chen Zhuguo, commander of the 12th Submarine Group and captain of the 1901 boat, stood up and motioned to the observation non-commissioned officer beside him to continue to monitor the sea surface.

Because of the concept inherited from the Austro-Hungarian Navy, and different from the way the Japanese Navy used submarine forces, under normal circumstances, the main target of the Chinese submarine forces was on the bodies of merchant ships, and submarines were not encouraged to launch attacks on warships. Because that often means a thrilling chase, and the probability of the submarine suffering losses is extremely high. But this time it was different, the submarines were before departure. The Submarine Command issued instructions that in the event of an enemy fleet, the submarines should find the enemy's fleet and take the initiative to launch an attack in order to disrupt the offensive rhythm of the Japanese fleet.

This is a difficult and dangerous task.

Chen Zhuguo left the command cabin and went to the dining room, where he and the co-captain and the chief navigator studied the sea area where the Japanese fleet targets might appear.

The submarine forces have been informed, and at the moment Ozawa's fleet has launched two waves of attacks. Although the fleet thwarted the Japanese attack, it was still in danger. But so far, the air search force has found no trace of the enemy.

"The enemy is definitely 300 nautical miles away from our fleet, and the Japanese Navy is equipped with 'Type 99' shipboard attack aircraft with a maximum range of 1,700 kilometers, while the maximum range of 'Zero Battle' is even farther than that of 'Type 99', and it is entirely possible to launch an attack from 400 nautical miles away. And the reconnaissance range of our fighters is limited to a range of 300 nautical miles, and it is normal that the enemy fleet cannot be detected! Sailing, Lin Chen frowned and looked at the chart and said.

"I feel the same way. The question is whether the enemy is currently in the north or in the east? Chen Zhuguo said.

"I think it's in the east!" Deputy Captain Xie Xian said, "At present, there are about 33 submarines in the northern seas, and it stands to reason that the Japanese fleet cannot avoid their search, but there is no news so far, and it is obvious." To the east, where we have relatively few deployments, the Japanese. ”

"Well, the probability that the enemy is on the east side is much greater." Chen Zhuguo picked up the two-legged gauge and gestured on the chart, "We will continue to search eastward, and inform the other submarines of our team to also concentrate on this sea area, if we move at full speed, we will be able to reach there in about two hours." ”

Since most submarines are currently equipped with underwater snorkels, in fact, submarines have a higher speed when they are in the depth of the underwater snorkel than when they are on the surface. However, there is also a problem in this way, due to the problem of the strength of the radar antenna and periscope, when navigating at underwater altitude, neither the periscope nor the radar can be used, and the submarine can only rely on sonar to capture surface targets, and the monitoring range and the ability to capture targets will be greatly reduced.

The No. 1201 submarine is the latest SMU41 ocean-going attack submarine assisted by Austria-Hungary to China, which is powered by four Steyr 5,200 horsepower diesel engines and two 4,600 horsepower main propulsion motors, and can reach a maximum speed of 23.5 knots when using the main diesel engine to dive at exhaust pipe depth, which is one of the fastest submarines in the world. If you sail at maximum speed, it only takes more than 2 hours to reach the target area 50 nautical miles away.

However, because there will be an obvious track on the sea surface, the probability of the submarine being spotted by enemy patrol planes will increase significantly, and the danger will naturally increase exponentially.

However, the Japanese apparently did not pay enough attention to the underwater threat, and Ozawa's fleet focused all its attention on the attack on the Axis surface fleet, and the 12th Submarine Group advanced rapidly underwater without encountering any trouble.

At about noon, the Project 1201 submarine finally arrived at the target sea area without any problems.

At this time, the Sashijun fleet had withstood three waves of attacks by Japanese fighters.

Although Ozawa's plan was good, unfortunately, due to the huge attrition in the war, the Japanese Navy's well-trained carrier-based pilots in the early days of the war were almost completely lost during the previous sea and land campaigns, and the new carrier-based pilots were unable to complete the tactics that required such a high level of technology and training as planned. In the second attack wave, when the Japanese attack aircraft group had been flying for more than two hours, most of the pilots' physical strength and endurance had reached the limit, and after being intercepted by enemy fighters with absolute superiority in numbers, most of the Japanese planes were unable to break through the interception because they could not complete the correct maneuvering maneuvers, and were shot down, and only about one-sixth of the planes were able to complete the bomb dropping.

The Japanese planes that desperately broke through the interception of the Axis fighters were hit by the anti-aircraft guns of the Axis warships when they flew over the fleet, and the hit rate was very high, and the Japanese planes suffered heavy damage, and finally only 12 planes completed the attack, and the aircraft carrier "Prince Albert" was hit by two near-miss bombs, killing 12 people and wounding 46 people, the rear elevator and hangar oil supply pipes were damaged, and caused a fire at the rear of the deck, but the fire was extinguished very quickly. The aircraft carrier "Zhejiang" was hit by a bomb, killing 1 person and wounding 14 people; Another Japanese plane was hit and crashed into the anti-aircraft cruiser "Cullen", causing minor damage to the large cruiser.

In the second attack wave, the Japanese lost a total of 98 fighters, including 42 bombers, 24 torpedo planes and 32 fighters, and only 31 planes returned to the aircraft carrier.

However, about half of the 65 fighters of the Japanese third attack wave were separated from the group in the middle of the way, and they were unable to find the target of the attack, so they could only return in vain. Iwami Shaosa commanded the remaining 30 fighters to turn to the latest position of the Sashijun fleet according to the report, but on the way they were intercepted by about 4 squadrons of more than 60 Italian fighter units, and after a fierce air battle, 9 fighter-bombers and 4 torpedo planes were shot down, and the surviving fighter-bombers also hurriedly threw away their aerial bombs, thus losing their offensive ability and had to return in a huff.

Now, Sa Shijun has also judged the general direction of Ozawa's fleet, and is directing the fleet to turn around and quickly approach the enemy fleet to the east, and the distance between the two sides is close to the range of 300 nautical miles. (To be continued.) )