This zigzag "Zhi" is a safe passage in the Yuguan sea area, in addition to this path for our own ships to enter and exit.

On the outskirts of this several miles wide harbor, all places are covered with mines.

Shen Mo began to develop this type of experimental mine nine years ago, and during this period he experienced countless experiments and improved processes.

Now, in terms of safety and power, it has fully met military standards.

Especially the power, according to Shen Mo's design, no matter what type of warship, the Song Dynasty mine must be destroyed by one thunder.

So according to Shen Mo's standards, even the gunboats driven by the Mongolian army were four times larger than the current displacement.

When they hit a mine four meters deep underwater, they would be immediately sunk! As for the secret of the three Song Dynasty gunboats returning to the harbor safely, it is because they always observe the safety benchmarks used to indicate the waterways on the landing.

These benchmarks are represented by two flagpoles in the distance during the day and two lighthouses of different colors at night.

All the steam gunboats have to do is adjust the course until the two flagpoles on the shore overlap together, which is their safe course.

To be on the safe side, the Navy even set a turn on the safe passage.

When the warship looks at the two overlapping benchmarks in the northeast direction and walks until the two overlapping benchmarks in the northwest direction, then turns around, aims the bow of the ship in the northwest direction, and continues to move towards the other two benchmarks, you can finally get out of the minefield.

But how could the Mahaye fleet chasing behind him know these things?

They were eager to achieve success, so they naturally bumped into the powerful thunder array under the vast blue waves.

Fortunately, Mahaye realized it early, and finally stopped his horse and did not let all ships plunge into the minefield.

He is now in a state of silence and does not know how to deal with the situation in front of him.

But opposite him, the three Song Dynasty gunboats ignored Mahaye's hesitation and confusion at all, but fired the cannon without hesitation! Along with a minefield, Mahaye's fleet now had insufficient firing range, and the shells could only fall into the sea in vain.

However, the Great Song warships in the opposite bay can be beaten hard on the head of the Mahaye fleet.

Then Mahaye and his sailors were surprised to find that the small gunboat opposite was less than half of his length and was about one-sixth of his material. There were so many artillery numbers on the opposite side! When he saw the flames coming out of the side of the Song army's gunboat, Mahaye closed his eyes in pain! There were two rows of upper and lower rows on the side of one of his mother's small boats, and nearly twenty cannons were firing at him! The cannons on the side of the other person's boat were equivalent to the number of artillery of his huge gunboat, and their cannons were many times stronger than him! Mo Keye, who had never known what the steel keel was, suddenly thought crazy: "How did they do it?

If this were Mongolian gunboats, one of them would be blown down by themselves!"

...When the entire Mongolian fleet saw the flash of artillery, it would be unnecessary to avoid and dodge any action.

They listened to the "wow" high-frequency whistling sounds from far to near in the air, and watched the shells get closer and closer to them! Then sixty shells on these three Song Dynasty gunboats landed in the middle of the Mongolian fleet like hail.

The shells roared past and smashed into the water, and the explosion brought out a high column of water.

One shell even penetrated the thin sail, and cut off one third of the mast supporting the sail.

Seeing more than 60 shells landing on the front, back and left and right of the gunboat, all the Mongolian soldiers were extremely nervous... At this moment, they were walking back and forth between life and death! Fortunately, the warships of their fleet dispersed their hunting formations when they charged before, and they were not squeezed too tightly.

These sixty shells did not hit the hull of any gunboat in the sparse fleet! At this time, many people in the entire fleet immediately breathed a sigh of relief, and at this time Mahaye was so nervous that his hair was about to stand up.

Cross-fire! The first round of volleys of the Song Dynasty artillery formed a cross-fire in the middle of his fleet. At this moment, two words suddenly flashed into Mahaye's mind... It's over! Let's talk about it here that gunboats on the sea use artillery to fight against cannons, not like shooting with rifles, aiming at the opponent's warship with cannons, and hitting directly.

Because the artillery shells are heavy and the shooting distance is extremely long, they walk on an extremely high parabola when flying.

Especially the poor artillery and inferior gunpowder of the Mongolian army, the parabola caused was even higher.

Therefore, their farthest range when firing cannons was actually lifting the muzzle to forty-five degrees.

So even if the shells hit the opponent's warship, they were all smashed from a high place.

In this case, the Mongolian army artillery had to shoot targets one mile away, and the artillery often had to be adjusted several times.

The first shot went far away, and the second shot went closer.

Until the artillery on their gunboats, when a certain fire is opened, the shells will be scattered in front and behind the enemy warships at the same time. This situation is called "cross-fire".

Once a cross-fire occurs in a naval battle, it means that the party that fires the artillery has accurately tested the distance between the artillery and both sides.

It is already a matter of time before continuing to fire artillery and hit enemy warships... In fact, the Mongolian army was extremely lucky to have fallen unscathed in the rain of bullets in the mid-squadron.

But of course Mahaye knew that the speed of the Song army's artillery fired several times that of his.

In other words, after a few breaths, when the next round of artillery fire from the enemy gunboats is fired, their fleet will face a catastrophe! Should we retreat?

At this time, in front of Mahaye, such a dilemma of life and death arises!...There are many factors facing Mahaye now, and the first thing is the overall situation of the battle.

When his fleet arrived at Yuguan, it was clearly seen by his own land troops.

At this time, the Mongolian army north of Yu Pass must be attacking the city wildly, and his fleet must attack from the rear as soon as possible, otherwise this fleet would be in vain.

So there are two ways in front of him, one is to rush through this minefield to the death.

If twenty gunboats could be exchanged for such a price, Mahaye would do it without hesitation! Because after passing through the minefield, he could launch an attack on Yu Pass from both north and south on land and at the sea at the same time as the original plan.

This is the best result for him, but it also has a disadvantage.
Chapter completed!