The North Carolina was also very quiet because Ramons brought the submarine into combat.

Although the Central Theater Command issued an order to advance at full speed to Ramons, in the US submarine force, the captain's tactical command was higher than the battle command of the rear command. After receiving the order, Ramons did not do the first thing he did not accelerate the North Carolina, but to maintain the original speed.

About half an hour later, Ramons reduced his speed to twelve knots and cast drag-and-drag sonar at the same time.

Like the Shark, the North Carolina cannot use towing sonar during rapid navigation. First, the towing rope may be pulled off, and second, the towing sonar during high-speed navigation will produce obvious spoiler noise, destroying the concealment of the submarine and making the sonar lose its due value under the interference of self-noise.

Then, the North Carolina adjusted its course and ran towards the Troy underwater peak.

Ramons firmly believed that after the "unidentified" submarine released the communication buoy, it did not sail eastward, but stayed near the Troy underwater peak.

It’s not about how clever the opponent is, but there is no need to take risks and speed up the departure.

Nuclear submarines are not conventional submarines, and there is no problem of exhausting electricity from the battery, using oxygen and fresh water. As long as there is food in the cold storage, they can stay in the sea. Under extreme circumstances, the continuous activity of nuclear submarines exceeds 120 days, and an attack nuclear submarine from the US Navy has also set a world record of 186 days of continuous activity. The "unidentified" submarine came to pick up the militants attacking the Trident, and must have reserved a lot of food. The departure time will not be too long, enough to stay in the sea for dozens of days.

As long as you are a little patient and find a place to sit in a sinking position, you can wait until the US military gives up the search and sneak away without any danger.

If you change your position, Ramons will do the same.

Ramons decided to search carefully for the waters near the Troy sea peaks and leave the mission of searching east to electronic warfare aircraft and anti-submarine patrol aircraft.

Performing anti-submarine search missions is the best way to attack nuclear submarines in the Virginia class.

On the North Carolina, in addition to the drag sonar hanging behind the butt and the side sonar posted outside the pressure-resistant shell, there is also a search weapon: high-frequency active sonar equipped under the head of the submarine.

When designed, this sonar was originally used to search for underwater minefields and mine hunting.

In actual use, submarine soldiers discovered that high-frequency active sonar has very outstanding submarine topography surveying and mapping capabilities. Using this map mapping capability, the "Virginia"-class attack nuclear submarine can not only draw underwater maps in unfamiliar waters, but also use terrain tracking to determine whether the submarine deviates from the route during submarine. If you fight in the nearshore seas, or deploy special forces in unfamiliar waters, you can also detect various possible risk factors underwater, reducing the dangers faced by submarines and special combat personnel.

It is naturally no problem to detect submarines nearby.

Compared with the bqq-10 attack sonar, which is also installed at the bow, high-frequency active sonar has one outstanding advantage: the emitted high-frequency sound waves are rapidly attenuated in seawater.

The operating frequency of attack sonars is very low because low-frequency sound waves are not easy to attenuate in sea water and transmit distances very far.

Scientific research has proved that the low-frequency sound waves emitted by male blue whales during estrus are transmitted thousands of kilometers away and are heard by magnetic blue whales in estrus.

When working in an active manner, the bqq-10 can accurately lock submarines tens of nautical miles away.

It is both an advantage and a disadvantage when it is spread far.

If you have occupied a favorable position and the enemy boat is completely unaware of it, a powerful attack sonar is like a bright searchlight that can leave the enemy boat nowhere to hide. If the situation is the opposite, or if you don't know the specific location of the enemy boat, using low-frequency active sonar is like holding a bright flashlight in a dark room, exposing yourself to the enemy boat at a glance.

High-frequency active sonar solves this problem.

Because after passing through several kilometers, the intensity of high-frequency sound waves will attenuate below the background noise of the ocean, it is difficult to be discovered by enemy boats ambushed nearby.

If the distance between two submarines is only a few kilometers, it is like hand-to-hand combat.

Ramons firmly believed that the "unidentified" submarine was sinking somewhere on the Troy Undersea Peak, because within a radius of dozens of nautical miles, only the Troy Peak stood tall on the seabed, the top of the mountain was less than 200 meters away from the sea surface, and on the mountainside with a depth of less than 600 meters, there were dozens of relatively gentle hillsides suitable for submarines to sink. Leaving the Troy Undersea Peak, the depth of the nearby sea area was more than 2,000 meters.

In this world, no combat submarine can dive for two thousand meters.

If the "unidentified" submarine is not planning to sit on the bottom of the sea, why release the communication buoy near the Troy sea peak?

Fortunately, the Troy Undersea Peak is a lonely peak.

It only takes a few hours to search this mountain.

After approaching the Troy Undersea Peak, Ramons lowered his speed to eight knots, allowing the North Carolina to detour along a route of 500 to 700 meters from the slope of the peak, scan each slope with high-frequency active sonar, and then cross-compare with the undersea map stored in the computer.

Any submarine is not small, and its appearance is very obvious. Even if it is buried in the sand, it can be seen.

At this time, Ramons ignored something that had just happened.

When the North Carolina slowed down and turned, the side sonar array and dragged sonar detected an abnormal noise, and the computer thought it was the collapse of the undersea mountains. The sonar told Ramons about this discovery, because no other abnormality was found, so Ramons did not take it seriously.

This sea area is just at the junction of the Indian Ocean plate and the African plate. The Troy Undersea Peak is the product of the squeeze and uplift of the two major plates, and the geological activity is very fierce. A few years ago, a submarine earthquake in the Maldives Islands raised the entire archipelago by 0:5 meters and triggered a tsunami of more than ten meters high, killing thousands of people in coastal countries in the Maldives, India, Sri Lanka, Pakistan and East Africa. As for the faint earthquakes that did not cause geological disasters, they occur several times a day.

Maybe a rock slid down and fell on the hillside.

Besides, the collapse site is southwest of the Troy Undersea Peak, dozens of nautical miles away from the North Carolina. Unless you use attack sonar and proactive working methods to detect, you can only adjust the course again and change the counterclockwise search method to clockwise.

Dragging the sonar several kilometers long, it is very close to the Troy underwater peak, so it is not easy to change the course.

Maybe, dragging the sonar will hang up the protrusions on the undersea peaks, causing unpredictable consequences.

Ramons doesn't want to risk losing hundreds of millions of dollars in dragging sonar for a vague noise signal.

According to his arrangement, the North Carolina entered the search channel northwest of the Troy Undersea Peak and began to sail around the undersea Peak.

At this time, the Shark also took action.

Although the noise of the North Carolina became weaker after slowing down, mixed with ocean background noise, which exceeded the limit of the human ear’s resolution, the Shark’s computer was able to filter out some ocean background noise and find out the characteristic noise of the North Carolina.

By comparing it with the digital information of the characteristic noise in the database, you can accurately grasp the whereabouts of the North Carolina.

These tasks are automatically done by the computer, and the processed target signals are displayed on the screen for the submarine commander to make tactical decisions.

"The target sails counterclockwise?"

"Yes, it's about fifteen nautical miles ahead of us, and it seems that we are going to bypass the Troy Mountain."

Zhou Yusheng frowned, feeling a little incredible.

"Maybe, the Americans know that we are still here." Yang Yuanfan whispered.

"It's not that we know, but that we guess." Li Xiaoming walked to Zhou Yusheng and said, "If we knew we were here, the 'North Carolina' would come to us and even directly fire torpedoes at us. The US captain guessed our intention to launch a communication buoy, but he didn't know where we were hiding. Nearby, only the Troy Peak could be used for the submarine to hide, so he asked the submarine to detour and wanted to drive us out."

"Maybe I want to find us."

Li Xiaoming was stunned for a moment and said, "The North Carolina does not use active sonar. If we can detect us with passive sonar, we will not be sailing around the Troy Mountains."

"In addition to attacking sonar, the North Carolina has other active sonars." Zhou Yu said with a breath, "The Arabian Sea is one of the main active sea areas of US submarines. The US military must understand the seabed terrain here and draws a fine seabed map. Using the active sonar drawing function and comparing it with the seabed terrain map you have mastered, you can find where changes have occurred, so as to find a submarine that sinks to the seabed."

"In this case, we have to follow."

"Don't worry, wait for the 'North Carolina' to go farther."

Li Xiaoming frowned, but did not object, because the two had already agreed that the tactical actions would be fully commanded by Zhou Yusheng.

"Guangyang, when will the 'North Carolina' fully arrive behind the mountain wall?"

"Half an hour later."

Zhou Yusheng thought for a while and said to Xia Hongyu who was guarding the weapon console: "You go to the torpedo cabin. When I order water to be poured into the torpedo cabin, you will be able to operate it yourself to minimize the sound."

Xia Hongyu nodded and left the command cabin.

"Old Zhou, are you going to act seriously?" Yang Yuanfan was a little shocked, "Didn't we agree? As long as the Americans don't open fire, we won't provoke a conflict."

"Old Yang, be prepared for any trouble." Li Xiaoming explained to Zhou Yusheng.

"But……"

"Don't worry, we won't fire first, but we can't sit and wait for death. The Americans dare to act rashly, so I'll knock it into the sky." Zhou Yusheng smiled at Yang Yuanfan and said to Lu Chengfeng, "Based on the route data of the 'North Carolina', calculate its route behind the mountain, and then set up a tracking route. Don't forget to take into account the impact of the mountain. I don't want to have a face-to-face fight with the Americans."

Lu Chengfeng didn't have so many problems, he got busy climbing on the chart table.

The command cabin was quiet again, but this time it was very short, less than half an hour.
Chapter completed!