Submarine communication under water is a technically challenging task.

Since seawater is equivalent to a huge conductor and has a good electromagnetic shielding effect, a submarine that is submerged underwater can hardly receive any shortwave signals. The various electromagnetic waves commonly found in the air, as long as they enter the seawater for one or two meters, almost Just disappeared.

Therefore, at the beginning, because there is only one way of radio, the submarine has to risk floating up to receive and send texts. This is quite dangerous. It’s just a matter of receiving. If it’s a telegraph, as long as it radiates electromagnetic waves, it will immediately Invite a large number of anti-submarine aircraft.

In the latter part of World War II, the Hans' wolf pack tactics were shattered in this way.

In order to solve this problem, buoy antennas or buoyancy antennas have appeared, that is, the antennas are deployed on the water surface so that the submarine can also transmit signals underwater. In fact, there is still a problem of submarine self-exposure, because the submarine uses short-wave communication at long distances, and its signal itself is not kept secret, and it may be intercepted and deciphered by the enemy, and the position of the submarine can be measured, and there are also buoy antennas exposed on the surface. The possibility of being detected by enemy radar.

Therefore, after years of research, long-wave communication has been confirmed as the most suitable underwater communication method.

Seawater has a strong absorption effect on electromagnetic wave energy, but it is different for electromagnetic waves of different wavelengths. The shorter the wavelength and the higher the frequency, the greater the attenuation in seawater. But electromagnetic waves with longer wavelengths can penetrate a little bit of sea water. The longer the wavelength, the stronger the penetration of electromagnetic waves.

Signals sent by very long wave and ultra long wave stations can enter water from tens of meters to more than 100 meters.

However, this kind of communication requires a huge antenna, which is hundreds of kilometers at every turn. At the same time, the data transmission speed is also quite slow. A packet of tens of bytes has to be transmitted for half an hour. During the war, it will be used to ensure absolute privacy.

Now there are communication satellites, and the submarines of Han State routinely carry out satellite communications every day, communicate with the base briefly, and then dive into the water again.

As long as it is not anti-submarine aircraft flying everywhere, always searching for the state, it is not difficult to find this kind of brief satellite communication and locate it.

"Report, got news from 320 boats, behind them, there was a bear country submarine following them." Back on the bridge, I heard the report.

Sure enough, the Xiong people were following them. Fortunately, they sent 320 boats and attracted a Xiong country submarine to follow. In this way, the real submarine that is ready to launch the mission guarantees better safety.

"Yes, let them dangle on the sea first, and when our launch mission here is completed, let's go to the Xiongguo submarine for revenge!" General Zhao said, patting the table.

I was humiliated by the Xiong Country submarine last time. This time, I must have revenge.

The 320 submarine, at the depth of the snorkel, continued to sail silently at a speed of five knots.

"Xiong State's submarine has been following us all the time. These Xiong State submarine soldiers are really skilled pursuers!" Captain Lei couldn't help sighing as he listened to the report of the sonar soldiers.

Your own submarine has very good quiet performance and is sailing at a low speed. The opponent is behind you and chasing at a distance of more than 30 nautical miles. It is simply an expert.

On the oceans, the submarines of the Bear Country and the Eagle Country often engage in such silent confrontations underwater, and their experience is very rich.

Originally, Captain Lei could not suppress his excitement, and wanted to fight the submarine behind him and compete fiercely, but now, his own experiment has not yet started, so he can’t change, otherwise he will lose the opponent. , It will be detrimental to the task.

"Hey, it's weird, and there is a sound." The sonarman whispered, closing his eyes, listening carefully, and carefully turning the **** of the sonar device a few times. Finally, when he opened his eyes, he already had a judgment: " Behind the Xiongguo submarine, there was another Los Angeles-class submarine!"

In the mid-1970s, the Los Angeles-class nuclear submarines gradually entered service, rapidly renewing the underwater power of the Eagle State Navy and becoming the backbone.

In the ocean, the Los Angeles-class nuclear submarine quickly became the main force in the confrontation with the Xiong State submarine. Now, the Xiong State submarine is chasing its own side, but unexpectedly, behind them, the Eagle State submarine is also chasing them.

The mantis catches the cicada and the oriole is behind.

"Continue monitoring." Captain Lei became even more excited. When his superiors decide to do something, what should he do to force all these submarines out of the water?

Well, think about it.

Underwater is a silent world. At this time, just hundreds of nautical miles away from them, Great Wall 200 is also sailing smoothly.

It was in a state of floating on the water at this time, and the bow of the boat split with splashes, and constantly tossed and rolled over. On both sides of it, there were two fishing boats, accompanied by left and right, and moved forward together.

That’s right, the warships in the naval port are all the enemy’s attention. There are also submarines watching under the water. Now, after quietly coming out, they merged with the two fishing boats and drove to this predetermined sea area without anyone noticed. .

This large submarine has a surface displacement of more than 2,000 tons, and it has reached 3,000 tons underwater, which is the same level as the Luda class. The huge hull, nearly one hundred meters in length, is like a whale. During the voyage, several crew members are carefully checking on the deck.

They were wearing white navy shirts, and behind the sailor caps, the black hood belt was waving with the sea breeze.

The deck of the submarine is not flat. The streamlined deck is easy to fall. If you fall into the sea, the consequences are unpredictable. However, no one is afraid, everyone is carefully inspecting it.

"The inspection is complete, the launch tube is in good condition." A young man raised his head and shouted loudly. His face was serious but also green. It was the young man Qin Guan met who wrote the suicide note.

He is responsible for the inspection task.

"Return to the boat." On the command tower, the captain of the car had a solemn expression and gave orders loudly.

A famous submarine soldier got back into the submarine, and the last young man expertly closed the hatch. This simple action was once neglected. As a result, the submarine sank completely just after it was launched.

"Report to the superior that we are ready and can conduct launch experiments at any time." The captain of the vehicle shouted to the political commissar below.

Waves flew to the satellite, and then to the fleet. Soon, news from all quarters came. The splash zone is ready and salvage operations can start at any time!

"Ready to launch, three hours countdown!"