The sound of the sirens that resounded throughout the ship made Wang Yu have to give up the intention of filling his stomach, put the noodle bowl back on the table, and hurried back to the bridge.

The siren sound came from the ship's siren early warning device.

This is a device that will warn when a siren reacts within 75 nautical miles of a warship, and it is also one of the key equipment that humans in that world can protect themselves against sirens in the past.

Sirens have some special features, that is, full-range radar stealth, their hulls, or the interference around the hull, seem to be able to absorb or disrupt radar waves, rendering the traditional radar useless.

This peculiarity of the siren warship also made the response to the initial outbreak of the human siren crisis extremely embarrassing.

It is indeed a desperate situation to not find the enemy, but the enemy can launch a surprise attack from all directions - the human feeling at that time is the same as the feeling of the big ships after the 4WD brothers were all killed in the first three minutes of the 4WD Brothers.

Humanity's proud weapons were not used, and the naval forces at that time lost more than 80 percent of their naval strength in the first wave of siren shocks, and humanity had to retreat to land and defend the coast.

This dilemma persisted for several years.

Until one day, the human research department analyzed the wreckage of the sirens destroyed in the offshore waters, linked some characteristics of the siren fleet, and came up with a "shipboard siren early warning device", which can give an alarm and indicate the general location when the sirens are approaching.

From this time on, the human fleet was no longer passively beaten like headless flies, at least it had the ability to be prepared when faced with the attack of the sirens.

Through the early warning device, Wang Yu found that the place where the siren reaction occurred was probably in the 305 direction of the battleship - this is the way to indicate the direction at sea, and the simple understanding of this number is the degree required to turn clockwise to the target direction with due north as zero and the ship as the origin.

The 305 direction represents the position of the siren about 35 degrees to the west of the battleship.

Wang Yu subconsciously glanced at the northwest.

Of course, he couldn't see anything now.

To put it bluntly, the siren early warning is the same as the radar warning receiver, providing only a vague direction, to put it bluntly, it is only a reminder, and there is no way to obtain the specific bearing, distance, course and other information of the siren.

After all, this device is only a passive early warning device, not an active detection device, and it is good to be able to tell you which direction there is a siren reaction - in the face of those warship commanders who complain that this equipment cannot obtain more specific information, the scientific researchers who do not need to go to the battlefield retorted.

It's much better than being beaten passively before, and what kind of bicycle do you need?

Wang Yu stopped the noisy alarm.

He pondered for a moment, whether to stay away immediately or to take the initiative.

Then he thought that if the sirens chased after him, his speed would not be able to escape, but it would make it difficult for his combat position to exert the firepower of the battleship, so since he couldn't escape and had to fight, it was better to approach the sirens first, use some special equipment of the battleship, set up a position, and take the initiative to attack.

After weighing it again and again, Wang Yu made up his mind.

He spun the steering wheel, hit about a quarter of the rudder, and slowly adjusted the course of the battleship.

The battleship tilted slightly on the surface of the sea and turned in the direction in which the siren reaction appeared.

Then Wang Yu slightly increased the speed of some battleships, and came to the eighteenth section.

Although there was a siren reaction in front of the battleship, it was not known how far the sirens were, and the sirens were very likely to be seventy-five nautical miles away, or twenty nautical miles away.

If it is an ordinary warship, it is estimated that it will have to be ready to meet the enemy at this time.

Because enemy ships can poke their heads out of the edge of the sea level and attack at any time.

But for this battleship......

The reason why the Annapolis is called a super battleship, in addition to the comprehensive enhancement of basic parameters such as fire armor, is mainly because of the black technology carried on some ships that is specially used to deal with sirens.

What's more interesting is that these black technologies basically come from the sirens themselves, that is to say, this is called using the technology of the sirens to fight the sirens.

After more than an hour of observing the sea level in the direction of the head, Wang Yu estimated that the distance might be about the same.

He easily walked to the electronic control panel on the side of the bridge, and with a few clicks, activated a special device that was spinning on the top of the bridge.

"Radar, activate!"

The bridge information system gives prompts synchronously.

[Surveillance radar is in use]

There are a lot of siren technology on Annapolis, such as the "Siren" control system mentioned earlier, which is one, and now I want to talk about the siren surveillance radar, which is another.

The "Siren Surveillance Radar" is based on the "Siren Early Warning", borrowing some new shipborne equipment developed by Siren technology - finally getting rid of the shortcomings of the early warning that can only be passively warned, so that human warships have the ability to actively detect the specific location of Siren warships.

Completely different from the principle of traditional radar, the principle of Siren surveillance radar is to detect the special "field" of Siren warships, so the detection is not limited by the size of Siren ships, from Siren battleships to small Siren destroyers, they will be detected within the maximum detection range of 40 nautical miles - and the closer the distance, the more accurate the information of the detected Siren battleship.

And this device has a more powerful function, that is, real-time detection without dead angles in the range of 12 nautical miles.

As long as the siren ship is within twelve nautical miles, the siren surveillance radar can unconditionally reveal the siren's location, whether the siren is hiding in a storm with poor visibility or hiding behind an island, it will be detected with precision and without delay.

However, this surveillance radar cannot be said to be perfect.

Nothing in the world is perfect.

This thing is too expensive to mass-produce, so in the navies of the last world, only a very small number of ships have installed this kind of surveillance radar.

Moreover, due to material constraints, the siren surveillance radar could not be turned on for a long time, and a single start could only last about forty-five minutes at most, and each start would enter a cooldown period of several hours.

Moreover, due to the immaturity of some technologies, the surveillance radar cannot be manually stopped after each start, and must be automatically stopped after its operation has completed its effective time.

This also disappointed commanders who had the idea of "constantly switching the radar on and off", such as Wang Yu.

Therefore, the commander of the warship using this siren surveillance radar must be aware enough to guess how far the siren fleet is about, otherwise the radar will be turned on and nothing will be found, then the radar will be in vain.

And now, after the battleship had advanced about twenty nautical miles in the direction where the siren's reaction appeared, Wang Yu turned on the radar, which would ensure that he had the greatest chance of discovering the siren's location.

The radar was turned on, but no sirens were found.

Wang Yu's face did not fluctuate, which could only prove that the distance between the sirens was a little farther than he imagined, but no problem, the distance between the battleship and the sirens should be narrowing, and within the duration of the radar, he should be able to spot the siren battleship.

Minutes and seconds passed.

Wang Yu was staring at the general direction of the siren's reaction on the early warning device, constantly correcting the course of the battleship, and staring at the information on the surveillance radar that could appear at any time.

The surveillance radar at the top of the battleship rotated constantly, detecting the sirens' warship.

Finally, after fifteen minutes of difficult waiting, the surveillance radar finally spotted the siren battleship.

Sirens were spotted at the maximum detection distance.

That is, the Siren fleet appeared forty nautical miles away, and it was in the direction of the battleship's advance.