"Therefore, the oxygen in the oxygen cylinder you carry is the only source of oxygen you can rely on when you are underwater. If you don't pay attention to the amount of oxygen left during the dive, and you may not be able to rise to the surface for a while, this is a very dangerous situation! ”

Mr. Kohama instructed with great seriousness, and pointed to the pile of oxygen cylinders prepared on the ship, and added:

"You must know that at this time, even if I have more oxygen tanks on the ship, I will not be able to rescue you in time!"

In this regard, listening to Mr. Kohama's narration, mainly among the three other tourists who listened to the lecture, Tokitsu Junya did not react, as if he felt that these were the most basic attempts and did not need to be explained, but among the other three tourists, one of them had some thoughts about Mr. Kohama's statement, and couldn't help asking:

"But...... When that happens, you can use this to ask for air with your diving partner, right? ”

Holding a snorkel connected to an oxygen cylinder in his hand, the tourist asked this question.

"That's right."

Listening to the words of this tourist, the other two tourists around him also nodded, as if they felt that what he said also made some sense.

However, hearing their conversation, Hattori Heiji on the side couldn't help but shake his head helplessly, as if he felt too naïve about their thoughts-

"With a snorkel, you can really lend air to people who are starved of oxygen."

In this regard, Mr. Xiaobin closed his eyes slightly, sighed and said this, as if affirming that their thoughts were somewhat reasonable, but then he explained their thoughts in more depth:

"However, if you think about it, each diver can only carry one oxygen tank at a time, and the partner who dives with you will also consume oxygen!

"So, if you want to borrow oxygen from your companion because you don't have enough oxygen, the partner who dives with you may not have the amount of oxygen left behind you is much better than yours.

"And, when there is a lack of oxygen in the water, the diver or diver usually panics. At this time, if you give your oxygen to the other party, it is possible that the other party will suck up your oxygen at once because of nervousness-

"After all, when people are panicked, their breathing becomes very flustered!"

Sharply, Mr. Xiaohama's tone became extremely serious, and he said very disapprovingly with the idea of borrowing oxygen from his companions when he was deprived of oxygen underwater:

"So if you think that a fellow diver can borrow this from you all the time, you're wrong."

Holding the snorkel on the oxygen cylinder and showing it off, Mr. Kohama continued:

"If there was such an emergency, would you give the other person the little oxygen you had left, regardless of your own life? Therefore, you should control and manage your own oxygen. That's all that matters! Do you understand! ”

In this way, after listening to Mr. Kohama's detailed explanation, the three tourists finally nodded embarrassedly, and then realized that the idea they had just made was too naïve.

So, Mr. Kohama continued:

"In this case, I see that you should all be just beginner divers, don't dive too deep this time, once you feel uncomfortable, hurry back to the boat, don't force it!"

In this regard, the three tourists present had no choice but to nod their heads in agreement-

"Well, that's a good point."

Listening to Mr. Kohama's explanation to the three tourists, Hattori Heiji couldn't help but nod his head and said with some approval-

"Hey! Pingji, what are you doing? The village chief, they're waiting to sail! ”

However, at this time, it seems that it has been a long time to watch on the dock next to the ship, and after Mr. Kohama has roughly explained the main points of diving, Toyama and Ha have already boarded the boat and headed towards Hattori Heiji, who has not yet boarded the ship.

So, Hattori Heiji hurriedly responded:

"Ah, that's right. Come now! ”

As he spoke, Hattori Heiji waved his hand at Gao Yuan, and said with some pride:

"Then I'll go first. This time, I might solve the puzzle before you do! ”

"It's good to have self-confidence, but this kind of thing may not be!"

Looking at Hattori Heiji's confident expression, Koshisui Nanatsuki smiled a little unconvinced, and at the same time looked at Takato beside him, and said to him:

"You say yes, Mr. Wise?"

"Hmmm......"

In this regard, in the face of such a situation, to be honest, Takato also understands that being able to go directly underwater and see the so-called undersea ruins will be of great help to this investigation, so it is possible that he who can't dive may not be able to find clues faster than Hattori Heiji, so Takato didn't make a very clear statement, but just echoed slightly.

Immediately, when Gao Yuan saw that the village chief on the boat was putting away the anchor and preparing to set sail, so he thought about the purpose of his start, Gao Yuan walked near the village chief and asked the village chief:

"That's right, Mr. Chief. I remember you said that there is a 'Giant Rock' on the east, west, and south sides of the island, so apart from the vicinity of the 'Giant's Rock' on the east side of this side, there are similar ruins under the waters where the 'Giant's Rock' is located on the west and south sides? ”

Some of them cared, Gao Yuan asked this question-

After all, according to the legend mentioned by the village chief yesterday, it is said that the "three giants" on the island are guarding the treasures of the ruins, and there are three "giant rocks" called "giants" in the vicinity of this island, so how many ruins are there under the sea?

At the moment, judging from what I talked to Hattori Heiji last night, the area where the so-called underwater ruins on the island are located is near the area where they are going to dive and check the area where the "Giant Rock" is located on the east side of the sea.

In other words, it is only known that there are suspected underwater relics under the waters where the "Giant Rock" is located on the east side.

So, what about the situation under the water where the two "Giant Rocks" on the west and south sides mentioned in the legend are located?

If the so-called underwater ruins are really related to the "Giant Rock" mentioned in the legend and the waters around this island, then it stands to reason that there should also be suspected underwater ruins near the waters of the "Giant Rock" on the west and south sides.

However, as far as I know since I landed on the island, it seems that the area where there are suspected underwater ruins only exists under the eastern waters where Hattori Heiji and the others are going to dive, and the west and south sides of the island did not even know that there were rocks that were high above the water in those two places before the village chief talked about that legend yesterday.

Therefore, after thinking about it, Gao Yuan still planned to ask the village chief for confirmation of this doubt first.

In this regard, listening to Gao Yuan's inquiry, the village chief replied with certainty:

"Nope. The underwater ruins here only exist under the eastern waters that we are now preparing to sail to, and there is nothing strange about them in the waters around the 'Giant Rock' on the west and south sides. ”

"That's ......"

Listening to the village chief's affirmative reply, Gao Yuan couldn't help but nodded, and didn't continue to ask, only said another word to tell the village chief to be careful and drive the boat, then turned around and left the dock and walked towards the west side of the island.

In this regard, the two of them, Nanatsuki and Xiao Ai, naturally followed the lofty pace-

"Mr. Wise, what do you think of the question you just asked the village chief?"

And when he heard the content of Takato's inquiry just now, when he was walking on the road, Koshisui Nanatsuki couldn't help but ask Takato curiously.

Seeing this, Gao Yuan shook his head and just said:

"It's not clear if there is an impact...... In short, let's take a look at the condition of the three 'Giants' first. After all, it is still impossible to understand the significance of the legend that the three giants are combined into one. ”

Hearing this, Koshisui Nanatsuki also recalled what he heard yesterday, and the legend about the undersea ruins and the "Giant Rock" mentioned by the village chief, he also nodded thoughtfully, and did not continue to ask more, so he continued to walk with Takato.

And Xiao Ai on the side, looking at Gao Yuan and Yue Shui Nanatsuki on the side, just chatted about the content related to the incident, and was silent throughout the whole process, just following Gao Yuan's side......

……

On the other side, after going out to sea in the village chief's boat, it didn't take long for everyone to come to the water near the bottom of the sea.

Here, after the village chief docked the boat on the sea, everyone in diving suits began to prepare to dive into the water.

Among them, because Hattori Heiji and Toyama and Ye are different from the other four, they are not inexperienced beginners, and the purpose of this dive is also to get closer to the area of the underwater ruins, so the two did not wait for the other four beginners, including Tokitsu Junya, after arriving at the designated place, the two took the lead and began to dive underwater.

In this regard, because he had seen the ability of the two of them to dive yesterday, Mr. Kohama didn't say anything to the two of them today, but after asking the two of them to pay more attention to safety, Mr. Kohama finally emphasized some precautions to the rest of the people who were about to go into the water, and let Hattori Heiji dive to the bottom of the sea with Toyama and Ye first-

"No matter how many times you see it, it feels spectacular!"

Soon, when Hattori Heiji and Toyama Kazuha dived underwater, the wide sea area did not hinder the two of them in the process of diving, and the two approached the area of the underwater ruins that seemed to be made entirely of rocks.

Seeing this, he just looked at this area that seemed to be surrounded by huge rocks from a distance, and Hattori Heiji couldn't help but feel a little shocked in his heart-

"Is it really possible that such a structure is man-made?"

With such doubts, Hattori Heiji gestured to Toyama and Ha, saying that he wanted to get closer to the underwater ruins to have a look.

In response to such a gesture, Yuanshan and Ye nodded, and if there was no objection, the two continued to dive down.

After bypassing a piece of undersea rocks, because the sunlight under the water began to be somewhat blocked by this rock, so in order to make the vision clearer, Hattori Heiji and Toyama Kazuha turned on the searchlight worn above the head of the diving suit, and went down a submarine slope all the way, and the two of them soon approached the edge of the suspected submarine ruins at the bottom of this water.

However, before the two of them could completely get close to the underwater ruins, keenly, Hattori Heiji seemed to sense something, turned his head to look, and saw that a boulder, which was also going down the slope of the seabed, rolled towards the bottom of himself and the distant mountains and leaves-

"Ahh What is that! ”

Suddenly, when he encountered such a large stone rolling towards him at the bottom of the sea, Hattori Heiji looked startled, and he was about to pull Toyama and Ye, who hadn't noticed the situation behind him, to dodge.

However, the underwater action is not like on land, when it has been submerged to a certain depth, the obvious water pressure directly affects the actions of Hattori Heiji, so that his movements seem to be slowed down a lot, although he grabbed Toyama and Ha's hand in time, but at this time, the large stone that rolled down also hit the two of them.

For a moment, the two people who were potentially underwater seemed to be pushed down by the falling stones, and after a while, the two completely touched the stone wall of the underwater ruins that were already close at hand.

But it was precisely because the stone wall blocked the way behind that the two of them stopped-

"Good, it hurts!"

However, when Hattori Heiji reacted from the encounter just now almost instantaneously, in his ears, there was a painful cry that Toyama Kazuha couldn't help but let out underwater-

I saw that she didn't even seem to bite the breathing tube in her mouth, and the blisters on the side of her mouth kept rushing to wail, and the culprit of all this, the falling stone, was actually pressing on the feet of the distant mountains and leaves at this moment, making her unable to move.

"Kazuha!"

Suddenly, seeing that Toyama and Ye were in danger, Hattori Heiji was also anxious to shout, but because he had to bite the breathing tube to breathe underwater, Hattori Heiji could only try his best to make such a barely audible sound-

"Are you alright?"

As he spoke, Hattori Heiji hurriedly tried to find a way to gain a foothold at the bottom of the sea, and then used his strength to prepare to move the stone that pressed against Kazuha's feet away from Kazuha's feet-

"No, it's caught!"

It's just that with all his strength underwater, in the face of this stone, Hattori Heiji couldn't move it even a bit.

And anxious, Hattori Heiji saw that there was no way to do it, so he carefully observed Kazuha's injury, and realized that after this stone collided with the stone wall of the submarine ruins, due to the irregular shape of the surface of the two, there was an irregular gap in it, and Kazuha's foot was caught by this small gap.

However, this gap is so small, if you don't move the stones, there is no way to get Kazuha out of danger-

"What should I do?"

In a hurry, Hattori couldn't help but take a big gulp of oxygen with an increased heart rate.

But right away, Hattori Heiji remembered what Mr. Kohama said when he was on the dock before, if you are too flustered at this time, the consumption of oxygen will be-

"Kazuha!"

For a moment, Heiji Hattori, who was trying his best to calm down, looked at Kazuha Toyama, who was in a panic because he was crushed by a stone.

Then, Hattori Heiji noticed that the oxygen level displayed by the barometer on the Waha oxygen cylinder was almost gone!

This sudden encounter made Yuan Shan and Ye breathe worse because of the panic just now, and the oxygen in her oxygen tank was almost insufficient-

"Damn!"

Feeling his heartbeat gradually quickening, Hattori Heiji felt an unprecedented sense of urgency......