This approach sounds a bit unreliable, no matter how you say it, the nautical chart can be identified casually, that is not a random drawing, but in fact, it is really like this, as long as the distance is set, the whole error will not be too large, unless the entire nautical chart is expanded to a considerable extent, such as the world map.

No matter how confident Zhao Xin is, he thinks that after a short time, he will almost certainly be able to cross the seven seas, open up a series of new continents, and even sail around the world.

In Magellan's time, their ships and measuring instruments were inferior to the developed Ding Navy, and they were able to travel around the world with the spirit of adventurers.

Zhao Xin, for the outline of the whole world, very clear, may not be able to draw a map, but the basic topographic map is still possible, for example, the North American continent, the South American continent, the African continent, with this, coupled with more accurate measurement methods, if it can't exceed Magellan, that's a joke.

In fact, in the future, what Ding Haijun has to do is to first determine the coordinate location where Ding Haijun is located, expand with this coordinate as the center, and fill in the determined coordinates in the outline made by Zhao Xin.

Setting this coordinate now can be said to be very inaccurate, and even for the future, embedding it in the future world map will cause huge trouble, but this chart with Ding Haijun as the core point of coordinates is very applicable.

If he can, of course, Zhao Xin also wants to do it in one step, and make the charts accurate at one time, he determines the equator, the Tropic of Cancer, and even in the future, the Leizhou Peninsula, the Taiwan Strait, and the easternmost main channel of Heilongjiang and Mohe, all in order to further accurately the coordinates of this latitude and longitude, but before that, a navigable chart that can be used is still essential.

The reason is very simple, Zhao Xin has also learned about the shipping of this era, as he guessed, this era of navigation, basically, is to travel close to the shore, no more than ten or twenty miles.

Some experienced captains and sailors, who have been running back and forth many times on this waterway, are more familiar with some landmark buildings, as well as special places in the bay, almost while referring to it, and a little bit of it, immediately go to the shore and find a leeward place to anchor.

This method is very safe, but it is not efficient, and in some places where the coastal situation is more complicated, it is easy to encounter pirates, but it is still acceptable for the huge benefits of navigation.

Zhao Xin never wanted this, he wanted a boat that could really go deep into the Deep Blue Fleet, so from the first time, he had very high requirements for the ship.

In this case, this coordinate is indispensable, and after these coordinates are determined, it is also very beneficial for determining the future shipbuilding of the navy.

In order to avoid getting lost and safe, the sea trial before the Dinghai Navy is no more than 50 miles at most, and once it is exceeded, it will quickly turn back to the sea, so that it is not easy to get lost, and the high peaks of the Dinghai Navy and the huge islands are the best references, as long as there is no big difference in direction, there will be no problems.

However, in this way, it is too close to the Dinghai Navy and the mainland, and it is not easy to test the performance of the ship going to sea.

The ocean close to the island or the continent is not the same as the real deep sea, and now, the Ding Navy has just started the test of those sub-projects, the largest is only more than a thousand stone sea ships, they are more of the old sea ships, far and near are not a big problem.

But now in the dockyard, the ships that are gradually being built and formed, they are real ocean-going sailing ships, this sailing ship, pinning Zhao Xin's ambition on the sea, such a ship, even during sea trials, it is impossible to test only near the island.

Zhao Xin knows the depths, and it is impossible for them to go deep into the ocean without a new ship that they are familiar with, for example, if they go to the trenches near Japan that are more than 2,000 meters deep to test, they may encounter accidents and increase their chances, and in case of a tropical storm, it is not something that these unfamiliar sailors can deal with.

It is impossible for them to go too deep into the ocean, but it is still possible to go about 200 kilometers deep and end at the position of the first island chain, that is, from the island of Japan to the island belt of Taiwan.

This distance, don't look very simple, in the Northern Song Dynasty, the sea ships have been to India and Arabia as far as tens of thousands of miles away, but they have never been to the mainland for more than 200 kilometers, otherwise, with the activity ability of the entire Chinese, how can they not discover Oceania.

From Southeast Asia to Australia, there is only a Timor Sea of less than 610,000 square kilometers in between, that is, a width of about 408 kilometers.

It's a pity that it is such a deep sea, which isolates the path of the Song people's advance, along the islands and the mainland, across dozens of kilometers, or 100 kilometers, there is no big problem, but once it exceeds 200 kilometers, it is a natural danger, this point, in the Yuanmeng expedition to Japan, encountered a kamikaze, after the whole army was annihilated, it never appeared again.

The first island chain, which in the 21st century, has become a chain that imprisons China's development, so that China has spent decades, can not break through the island chain, in this era, is just a wild land, maybe on some larger islands, some people, but some natives, they are simply unable to resist the elite troops from the Northern Song Dynasty, let alone the epoch-making fleet of sea ships.

Now, this idea is only in Zhao Xin's heart, and it does not assist the reality, once it is propagated, it is an unprecedented event for the navigation and shipbuilding of the entire Northern Song Dynasty, and there is almost no distance crossed in the entire Northern Song Dynasty ships.

In a sense, this island chain is, in fact, the difference between light blue and dark blue.

In the interior of the island chain, the depth of the water is relatively shallow, because the islands are dense, and the proximity to the mainland, the sea here, most of which is the continental shelf, because of the close relationship to the mainland, the wind and waves are not so big, after all, the wind is above the sea level, and the blockage is different from the land, there are many mountains and land, which is completely different.

Typhoons and tropical storms, formed at sea, are generally near the equator, and then spread outward frantically, even if they travel hundreds of thousands of miles, or even thousands of miles, they have not weakened much, and they often gradually strengthen when encountering some unique weather, and sometimes, the wind in the center will strengthen from seven or eight to more than 12.

However, once a typhoon landfalls, not to mention an island, the island can provide less, and it will weaken, and once it lands on the mainland, it will rarely affect how deep it is, and the land is like a heavy mountain, blocking the typhoon, so that the typhoon will quickly weaken and become a depression.

But in the ocean, it is not so easy, not to mention tropical storms and typhoons, let alone six or seven gale winds, in the deep sea and the offshore, these are two completely different concepts.

The average depth of the East China Sea is about 350 meters, but the deepest part is on the western side of Japan, and there is a trench 2,700 meters deep.

There is still a big difference between the deep sea and the shallow sea, which Zhao Xin, who came out of the consulting era, understands very well.

The reason why China can communicate with Japan, the narrowness of the Tsushima Strait is one aspect, along China's coastal waters, all the way around the Gulf Line of Korea, around a circle, to Japan, in the middle, will cross some more than 50 kilometers, or even a little farther in the strait, but once familiar, there is no problem, really directly from the hinterland of China, direct sailing to Japan, that was in the late Ming Dynasty, the sailing ships of the Age of Discovery, after the introduction to China, there are also measuring instruments such as sextants, only to have the ability to sail directly, before that, Most of it is walked slowly along the coastline.

This is the difference between the East and the West, the reason why the Pacific Ocean is called the Pacific Ocean is because of its large and flat, although there are many tropical storms, but the real average to every sea area, is relatively calm.

If it's in Europe, it's even more difficult, after crossing the English Channel, the North Sea, basically, it's about the same as the Atlantic Ocean, and when the waves are more than five or six meters high, they are almost everywhere.

If you don't experience wind and rain, and if you don't go deep into the deep sea, you will never be able to understand the horror of the deep sea, even if it is led by Zhao Xin, who has tested most of the sub-projects, so that this sea ship has all the conditions of the peak of the sail ship, and in the same way, the use of better steel, water tightness, and the popularization of machinery in all aspects will make their quality stronger than the strongest sail battleship, but after all, it has not withstood the test of the sea.

If you put it in history and archaeology, it is difficult for Zhao Xin to be able to do it for ancient cultural relics, whether it is age or true or false, but on the ship, especially on the sea ship that crosses the ocean, Zhao Xin really has no bottom.

This is a completely different, even very professional field, this field, Zhao Xin has never been in contact with, can only through experiments, to verify whether these things are correct, if there is anything omission in the middle, for these testers and seafarers, it is to exchange life for experience.

Zhao Xin attaches great importance to manpower and does not easily fill with human lives, but that is in the normal development, once there is no way to solve the problem, the necessary sacrifice is of course indispensable.

Zhao Xin's present is no longer the previous life, the doctoral student studying in the ivory tower of the university, but the Jiedu envoy of the First Army, this army is not a small army on the border of the Northern Song Dynasty, after his efforts, it now has at least 1.6 million people.

These people do not belong to the Dinghai Navy, except for a small number of people who have turned from Huainan East Road, as well as the Xiangjun who have migrated over, and almost all of the rest seem to have no household registration, and their household registration is still in place.

It's just that the environment in situ is getting worse and worse, for example, escaping from famine, such as disasters, coupled with the strength of the Ding Navy, they slowly come over.

In feudal society, the government decree stops at the county, and below the county, it belongs to the world of officials, they may have a huge threat to the ordinary people, but in the face of a Ding Navy envoy, their strength is not enough to see, as long as they don't make a big deal, there won't be too many people know.

With the development of the Dinghai Navy, countless money has been earned for the people, and the Dinghai Navy, no matter the environment, or even enjoyment, is far more than their hometown, as long as they are accompanied by the passage of time, they will gradually be assimilated by the Dinghai Navy.

Even if it is more than a million people, this is a huge burden, how much benefit you enjoy, how much responsibility you have to bear, even if it is for the more than one million people under his command, Zhao Xin has to hold on, it is impossible to bring these people to the ditch.

Zhao Xin is not a philosopher, and will not think about whether to kill one person for a hundred or a hundred for one, how much philosophical significance there is, whether people are equal between people and whether all beings are equal.

But as a superior person, he will naturally choose between one egg and ten eggs according to the general law, and he will definitely choose ten, not one.

Not to mention, Zhao Xin also has a lofty wish, that is, to lead the Northern Song Dynasty and the entire Han nationality to the peak.

Perhaps because of Zhao Xin's crossing, in this era, the Northern Song Dynasty has gone through a completely different path from history, and the powerful Northern Song Dynasty, coupled with Zhao Xin's targeted changes, must be completely different.

But history is a mirror, how much lying on the merit book, surpassed by others, overthrown by others, he can't relax, he must march forward, then he can't be soft-hearted, he won't deliberately let people sacrifice, but some necessary, essential.

Now, it is a bit far to say this, and those who go to the deep sea will not be able to perfect the navy in a short time, not to mention the charts and ships, even if these are already complete, there is no skilled, strong naval team, going to the sea, it is just a vain sacrifice.

The only fortunate thing is that at this moment, it is five or six hundred years earlier than the Age of Discovery.

Europe at this time was still at the end of the Middle Ages, from 476 to 1640, which was the most ignorant and darkest era in European history.

Europe during this period did not have a strong regime to rule. Frequent wars brought about by feudal secession, and the imprisonment of the people's minds by Catholicism led to the stagnation of the development of science and technology and productive forces, and the people lived in hopeless suffering.

The whole of Europe has not yet opened the age of sailing, even if there are ships, this ship is only limited to the Mediterranean, or the North Sea, not deep into the ocean, this era of Europe, they are traditional, dozens of tons of small boats, this ship, simply can not withstand the wind and waves, even along the coastline, it is impossible to go deep into a very far place.

For Ding Haijun, there is no other competition, there is no need to race against time to include the surrounding strategic places, as long as it develops slowly, step by step, he can get all the things he wants, and he can wait for time.