Transmigrated as the Crown Prince

"Captain, it seems that the 'Carp' has been sunk!"

In the distance, in another US submarine, the sonar operator had a sad look on his face and reported the bad news to the captain. But the next second, his expression suddenly changed. "Oops, the German destroyers are heading towards us!!"

"Damn it!" the captain ordered decisively without having time to remember the sunken "Crucian Carp". "Turn off the power system!!" As mentioned before, this is a very risky decision. Once the power system is turned off, the submarine can only move underwater. However, the experience of the "Carp" warned them that if they want to fight the German destroyers, then Just looking for death. He could only try his best and turn off the power system. The entire submarine just floated quietly in the 50-meter-deep water, hoping to avoid the search of the German destroyers.

Ping! Ping! Ping!

As the destroyer approaches, the sound waves hitting the submarine shell become louder and louder. The cavity effect amplifies the sound, and the sailors in the submarine can hear it clearly even without sonar headphones. The sonar operator promptly turned down the volume of the earphones to avoid damaging the eardrums.

Everyone was so nervous that they didn't even dare to express their anger. They looked at each other and communicated with their eyes. "What is this sound?!" They had never heard such a strange sound before.

"God!!" At this moment, the sonar operator suddenly shouted. "This is active sonar! The German destroyers are equipped with active sonar!!" Then he explained the principles of active sonar to the people around him as fast as he could. His uncle was an expert in sonic science and had heard about the principles of active sonar before. Unexpectedly, the Germans had successfully developed and equipped active sonar.

"What?!" Everyone was shocked after hearing this. According to the principle of active sonar mentioned by the sonar crew, even if they turn off the power system and maintain absolute silence, they cannot escape the search of the German active sonar!!

the captain asked hurriedly. "Is there any way to avoid active sonar detection?!"

The sonar operator's expression was uglier than crying. "As far as I know, there is only one, and that is to dive into the sea cline. The cline will refract the propagation of sound waves."

The so-called thalassocline is a water layer in which seawater parameters change significantly with depth. It refers to a water layer in which seawater temperature, salinity, density, sound speed and other conditions experience sudden or continuous changes in the vertical direction.

There are mainly thermocline, salinocline, pycnocline and sonic cline. Thermoclines are frequently present in the ocean and affect salinity, density, and sonic clines. Halocline often occurs in estuary areas or sea areas where there is a lot of precipitation, evaporation and melting ice. The pycnocline usually appears in places where seawater mixes, two water masses converge, river freshwater flows in, and water temperature and salinity suddenly change. Except for estuary areas and individual sea areas with particularly large vertical salinity gradients, the pycnocline is generally the same as the temperature jump. Layers overlap. The sonic cline is usually formed due to the uneven temperature, pressure, and salinity of seawater, and the sudden change in the sound propagation speed in the vertical direction.

These cleats play a positive role in underwater communications and submarine concealment. Hydroacoustic equipment works best in deep sound channels, and submarines sailing in deep sound channels can detect targets far away. Sonar signals emitted above the sonic cline are difficult to detect targets below the cline, and submarines that dive below the cline are less likely to be discovered. If the strength of the hydrocline is small, the upper boundary depth is deeper, the thickness is larger, and it is more durable and stable, it will form irregular sound reflections, significantly reduce the combat effectiveness of anti-submarine sonar, and cause difficulties in anti-submarine operations.

"Shet!" They don't know the hydrological conditions here. If they dive rashly, they may not be able to reach the cline even if they exceed the submarine's maximum diving depth!

Just as the captain was hesitating, the sonar officer's face turned extremely pale. "Captain, the German destroyer dropped depth charges!!"

After hesitating for a second, the captain decisively ordered. "Start the engine! Drain the water tank!!"

A few seconds later, the depth charges exploded above them. The loud sound caused the sonar operator to scream and take off his earphones. He felt that his ears were about to bleed, and his whole brain was rumbling.

The shock wave of the depth bomb explosion carried a thunderous momentum, and the seawater pressed against the submarine's shell with huge pressure! The steel plate of the rear shell of the submarine could not withstand this terrible impact, and it twisted and deformed instantly. A large hole was opened in the engine room. The seawater under five atmospheres of pressure seemed like a huge fist, and it smashed the several people in front of it. The sailor slapped him against the bulkhead. The seawater, which was instantly stained red with blood, rushed crazily into other cabins.

"Close the hatch! Emergency surface!" The captain issued an emergency surface command. The submarine drained water and surfaced as quickly as possible, and was very lucky to avoid the remaining depth bombs. When it surfaced more than 20 meters above the sea, the captain gave instructions to the correspondent. "When we surface, immediately send out the news that the German army is equipped with active sonar!" Otherwise, our submarine will suffer many losses.

As he spoke, he raised the periscope and saw that the German destroyer's guns were pointed in this direction.

"I hope they can take prisoners." Just as the captain prayed in his heart, he saw fire erupting from the muzzles, and then he knew nothing.

After sinking the submarine mercilessly, the German destroyers continued to search the sea area until they determined that there were no other submarines and then sent the news back to the fleet.

"Commander, we sank two American submarines."

Commander Hellman nodded. "Strengthen the alert and don't let them transport supplies to the island."

Oahu has been besieged by them for eight days. And even God is on their side. In the Pacific Ocean, which originally had plenty of rain, there was only one light rain on Oahu in the past eight days, which was not enough to moisten the throats of the island's defenders. In three or four days at most, these defenders will lose their combat effectiveness due to lack of water.

Another fleet sent to Midway easily captured Midway. Although all the facilities on the island were completely destroyed by the evacuated US troops, they did not expect to take over these facilities completely from the beginning. The accompanying engineering team has begun to repair the island's airport and port. Soon Midway Island will become a base for the German Navy.

In the underground headquarters on Oahu, Commander Wilson once again asked the question he had asked countless times. "Have you contacted the supply submarine?" His lips were dry and cracked due to lack of water, and his whole body looked depressed.

The correspondent replied weakly. "Commander, the supply submarine may be submerged. According to previous communications, it is already 50 kilometers away from here."

50 kilometers, even a submarine can reach it in less than six hours at a submersible speed of 5 knots.

Unfortunately, after waiting for more than ten hours, there was still no news about the submarine.