When Zhang Zhong and this ship, the urgent return of the Dinghai Navy, informed the Dinghai Navy that the pirates existed nearby, in the core area of the Dinghai Navy, in Zhao Xin's office, countless drawings were being rolled out, and Zhao Xin calculated according to various aggregated data, and filled the calculated results on the charts.

At this time, the nautical chart, centered on the Dinghai Navy, has occupied a large part of the Yellow Sea and the East China Sea, from the Bohai Sea to the mouth of the Yangtze River.

Even if there is only such a coastline of less than 1,500 miles, there are many points in it, most of which are on the shore, and there are more points that can be collected on the shore than on the sea, and it is more accurate.

After a long period of calculations, with the help of countless people to measure, the calculation of the nautical chart has been basically completed, basically, most of the places facing the land of the Dinghai Navy can be displayed on the nautical chart, even the estuaries of some small rivers, also marked.

This chart is not the most accurate, but it can already be used, as long as the error is strictly in accordance with the standard, it will not exceed 800 meters.

An error of 800 meters is an unforgivable error for the 21st century, even if it is such a rocket artillery, an unguided weapon, their error reaches this number, it is unacceptable, this difference is too far, the difference of 200 meters, it will reach 2 miles.

However, in this era, this is an unprecedented breakthrough in navigation, and I am afraid that it will not be possible for Europe to have nautical charts of the same specifications until five or six hundred years, or even six or seven hundred years later.

The voyage of hundreds of nautical miles has an error of 800 meters, that is, even if you miss the landmark, multiply it by two, it is only 1600 meters, 1600 meters, on the unobstructed sea, even under the premise of average visibility, you can see it, let alone have a lookout with a telescope.

Even, an experienced captain will not go to the extreme under the premise of multiplying by two, an error of 800 meters, after the adjustment of the experienced captain, choose the middle, or a partial point, the error will be less than 800 meters, or even 500 meters.

This requires experience, a mile of error, which is basically, for navigation, can be accurately judged, which will become the basis for going to the ocean, in a thousand, or even tens of thousands of miles of voyage, if it has been explored or recorded in the area, what if it is not recorded?

An error of 100 meters for hundreds of miles is acceptable, but under the premise of thousands of kilometers or tens of thousands of kilometers, this error is so large that there is no edge.

In the Pacific Ocean, if the angle is slightly worse, you may not be able to find land, but you will keep going around in circles, not to mention in some dangerous areas, once you enter, the ship will be finished.

800 meters, is the highest degree that can be achieved by measurement and calculation now, in the future, it needs to be accompanied by the determination of various precise coordinates, there will be a large-scale improvement, generally speaking, before the ranging unit has a huge improvement, the map is on the basis of the original, gradually accurate, this takes a long time.

Of course, Zhao Xin also has shortcuts, for example, the location coordinates that Zhao Xin remembered, maybe those positions, are not the most accurate positions, but with these, they can confirm each other, plus some ranging means, as well as the abundance of nautical charts, you can also complete some, and there is calculation, through non-stop calculations, so that the accuracy is higher.

For example, the minimum accuracy is 0.1 tools, not necessarily can not reach 0.05, because to the premise that the basic requirements of 0.1 have been reached, the rest is to continue to explore, maybe there is no accurate index, but some people with excellent experience, or can summarize something from the middle, through such a gradual determination and accumulation, in the future, to reach 200 meters, or even 100 meters, is not a problem.

It's just that this doesn't have much effect, even Zhao Xin knows very well that a nautical chart, to the current accuracy, even worse than now, is twice as bad, it is enough to accept, as long as the visibility is not extremely poor, as long as it is the future, a large number of lighthouses more than 40 meters high, completed in the entire Dinghai Navy, then the chart, a little worse, it doesn't matter.

At this time, Zhao Xin is basically finishing, and even next, he is not ready to complete the follow-up calculations in person.

The work of data calculation is too cumbersome, Zhao Xin has a lot of important work, it is impossible to waste time in such a calculation, Dingjun, with the increase in knowledge level, with the abundance of personnel, now there is not much shortage of personnel, as long as a group of training is good.

He has summed up some formulas, and even more precise formulas, and has also prepared some calculations on simple mathematical formulas, as long as there is a little introduction to mathematics, it can be carried out.

Before, he did it himself, just because, the Ding Navy did not have this chart, in order to avoid too much deviation, he had to go into battle himself, but now, with the gradual accuracy of the chart, next, there is a fixed ruler and law, too much difference, it must be wrong, as long as it is carried out in that direction, even if it is a waste, miscalculation, it doesn't matter, it's a big deal to waste time, it's completely different from the previous one.

At this juncture, the pirate appeared, which was really a bit unexpected by Zhao Xin, and even disrupted his plan a little.

Pirates, this from the sea after the shipping conditions, appeared, to be exact, pirates should be derived from the bandits, when there are boats on the river, the bandits began to appear, killing people and setting fire to the gold belt, this sentence is not wrong at all, robbing a boat, the income can be much greater than that of ordinary merchants.

The same is true at sea, the busy sea, since the beginning of the ocean-going merchant ships, there have been busy routes, in the current era, why some merchants, come from thousands of miles, for what, of course, to make money.

When a ship is only a few hundred or thousands of stones, in order to pay for the consumption generated by the voyage of thousands of miles, what they bring must be relatively valuable products.

Maritime merchants, at any time, are synonymous with wealth, a ship arrives at the port, and the simple display of things is as high as thousands, not to mention some terrible big merchants, they bring a shipload of goods, the total value even exceeds 50,000, or even 100,000.

In the face of such a large amount of wealth, rare treasures from the outside world, all attract the attention of pirates, when a person chooses this path, slowly there are more.

A key problem is that the average Chinese sailing ship, their speed is not fast, and the wooden oars facing the pirates are not their opponent's at all, which gives rise to a lot.

As early as the development of the Dinghai Navy, Zhao Xin began to pay attention to pirates, at that time, in the port of the Dinghai Navy, in the key places, seven or eight fortresses were arranged, which was enough to protect the entire Dinghai Navy, and what he guarded against was actually pirates

The development of the Dinghai Navy could not withstand the invasion of pirates, and the destruction of pirates was indiscriminate and violent, but the result of this violence was to make the entire Dinghai Navy suffer losses.

This point is unacceptable, even if it is a navy, there are not many troops, and the combat effectiveness is not strong, Zhao Xin also put the protection and army at the forefront for the first time, and the foundation of development is for a better future, but in the early stage, when it is relatively weak, in case it is attacked by pirates, the loss will be great.

For more than a year, there were no pirate attacks, and even the navy lived and worked in peace and contentment, and the development was extremely stable, they all thought that the pirates would cease to exist, but no one thought that the pirates would appear in front of him again in such a way, and they were so close.

90 miles, that is to say, if the pirates go all out, it will take a little more than 4 hours to reach the Dinghai, which is really not a very long time, and even in a sense, it is relatively short, which is a huge threat to the Dinghai.

The side of the couch does not allow others to snore, this point, not only the idea of the hero, but also the idea of the Dinghai, in case, Jin Haidao can really not pass the Dinghai Navy's layer by layer review, and finally land in the Dinghai, then the final result will be very terrible, if the Dinghai Navy can not be found at the first time, can not be the first time, through means, drive them down to the sea, in the end, once the pirates board the Dinghai, they will be crazy in the Dinghai, killing pirates without blinking, how much damage they will cause, How many people were killed.

As soon as he heard the news of the pirates, Zhao Xin decided to eliminate them, he had already controlled millions of people, as well as the huge output value created by these people, Zhao Xin had the confidence to fight the pirates, in his opinion, these inconspicuous pirates were wiped out in front of the lupine scarf.

However, after checking the navy, when Zhao Xin asked how many navies there were, he got a message that made him very helpless.

Ding Navy, there is not a single warship, this is a big problem.

Naval warfare, mainly warships, you can't imagine, when a warship doesn't have time, how you participate in naval battles, it's not naval battles, but child's play.

The Dinghai Navy may have developed particularly well in any other aspect, even beyond the imagination of the entire Northern Song Dynasty, but there are really not many ships, especially warships.

There are quite a few ships in the Dinghai Navy, and even some ocean-going ships, and some are even ships of the Northern Song Dynasty patrol team, all of which were obtained by doing everything possible under the leadership of Zhao Xin at the beginning of the establishment of the Dinghai Navy.

Merchant ships, in order to communicate with various places, the Dinghai Navy has concentrated millions of people, different from Bianliang, no matter how Bianliang is said, there is also the support of the surrounding Gyeonggi, Gyeonggi still has vast farmland, although these farmlands, and Jiangnan can not be compared, but it is basically solved part of it.

The Dinghai Navy is different, everything must be entered from the outside, the Dinghai Navy only has more than 300 square kilometers of islands, and there are too many things to be placed, such as factories, such as residences, and some municipal construction, so under the premise, it is impossible for the Dinghai Navy to have arable land.

In fact, even if there is, it will not be planted, and most of the places in the Dinghai Navy are green, and it is impossible to give a place to grow food, and even if it is, it will not be able to plant much.

All of them are shipped abroad, and these grains are the lifeblood, and the transportation of large quantities of grain is also inseparable from cargo ships.

In addition to cargo ships, in order to protect the safety of the Ding Navy, they also got some warships from the sea patrol battalion, but the warships of the Northern Song Dynasty, adhering to the characteristics of the traditional rivers, are not very large, there are some vehicles and ships, and there are very few others.

But these ships, in Zhao Xin's eyes, are nothing at all, their combat effectiveness is not high, of course, when there is no other choice, Zhao Xin also has to choose this, especially those patrol battalion ships, they themselves are for fighting, it's a big deal to get some more, how can it be better than the pirates' wooden oars boats.

However, in Zhao Xin's heart, he is more inclined to sailboats, this sailboat, itself is made with reference to the Spanish galleon, which is smaller than the original, but adds more mature things, as long as it is armed, the combat effectiveness will definitely be stronger.

Some people who don't believe in evil Zhao Xin still went to the shipyard to have a look, but got a good news, that is, a ship under intense construction, if it is urgently refitted, does not build a superstructure, but hangs the sails, it can be completed within 3 days.

This greatly surprised Zhao Xin's expectations, I thought that it would take at least ten days and half a month, but without building the superstructure and interior decoration, it could be completed, which is very good.

Although there is only one ship, this is a real sail warship, plus others, 4 ships with 1000 materials, these will be modified according to a certain method, maybe not like a sailing ship, it is a real warship, but it can also have four ballistas, dozens of soldiers including ships.

Under the efficiency of the navy, the ship was quickly prepared, a total of 13 ships, 12 of which were auxiliary ships, and what Zhao Xin liked the most was actually that sailing ship.

This 300-ton boat, all soft sails and dwellings, arranged with a spinnaker, their combat effectiveness is very strong,

There is one less layer of superstructure, but there are a lot of decks, through temporary arrangement, at least 36 ballistas can be installed, in this ballista has not even been on the ship, temporarily the whole sea, just bow and arrow and broadside warfare-based combat mode, this ballista, can be said to be a big killer.

Through some arrangements, for example, with the help of large machinery, the operation of the ballista can be reduced from 7-8 people on land to 3 people, there are enough openings on the deck to allow the ballista to be fired easily, and most importantly, the type of ballista.

In addition to the most basic and entry-level ordinary ballistas, there are also explosive, ignited, and specially aimed at sails, these crossbow arrows can greatly strengthen the ability of the ballista, and also make the combat effectiveness of the warship stronger, reaching the strength of being able to go to sea to fight.