Chapter 544 Technical Diving
Dark underwater world.
Bifang adjusted his posture in the water, concentrated his strength in his upper body, and swung his fist quickly. The tip of his fist broke through the sea water and hit the dolphin hard on the forehead.
The dolphin's skin is very smooth and soft. Bifang's punch was like a huge blade that quickly cut through the head of the dolphin on the carbon fiber plastic board padding the sea surface.
Although the damage was not serious, it still made the dolphin feel pain and turned over in the water.
It was stunned by the punch.
The bottlenose dolphin and its companions were stunned, not understanding what Bifang was doing. They swam around Bifang and made sharp cries in the water.
The huge noise in his ears mixed with the cries circulated in Bifang's brain. He could feel that the dolphin in front of him was asking questions.
It was puzzled by Bifang's behavior.
Unfortunately, the dolphin's question was not answered, but instead attracted more punches and kicks.
A few minutes later, the dolphin's tail fin slammed into Bifang's chest, and it flew away with its companions, no longer paying any attention to the stranger it had "rescued".
The enormous force slammed Bifang against the rock wall, shattering a lot of sandstone and gravel, but Bifang not only did not feel uncomfortable, but also laughed.
But it hurts so much.
Bifang covered his chest helplessly, his lungs were being compressed by the water pressure, and the dolphin's tail fin was like a battering ram, hitting him directly and almost making him vomit blood.
At this moment, Bifang felt short of breath in his chest, as if he had held his breath for too long. He retched and had difficulty breathing.
The bigger the animal, the stronger it is. The black bear hunted by Bifang was only 300 kilograms, but the bottlenose dolphin just now weighed more than 300 kilograms, or 600 kilograms, which is twice as heavy as the previous black bear!
It sounds incredible. The huge black bear that looks so ferocious actually weighs only half of the dolphins in the aquarium?
In fact, this is true. The weight of a male black bear is usually between 60 and 200 kilograms, but the weight of a male bottlenose dolphin can reach between 300 and 650 kilograms.
The reason why a black bear looks larger is entirely due to the visual effect of its fur and scattered limbs, and its mass is far less than that of an adult dolphin.
In the sea, not only is Bifang inconvenient to move, but dolphins do not have the same obvious weaknesses as black bears and are better at attacking and swimming. In a one-on-one fight, he does not have much chance of winning, let alone two of them.
Bifang didn't dare to use too much force just now, for fear that he would really provoke the other party and he might not be able to defeat him...
Leaning against the rock wall, Bifang bit the breathing valve to continuously exchange airflow to relieve the congested chest. The huge Niugang trevally was still stuck on the spear, and its tail fin swayed up and down with the water flow.
Above the sea, several cruise ships with colorful lights on are wandering in the distance. If you look closely, you can see the unique dolphin shape on the hull.
Dolphin Bay is a restricted area and few people go there. Only nearby fishermen come back to patrol occasionally, and even cruise ships will not approach easily.
Keke and Mandy stood in the shadow on the shore, not daring to show their heads. Occasionally, when someone passed by, they would quickly hide among the rocks and reefs, staring at each other.
Looking at the calm sea, they were both extremely anxious.
Bifang's strength is obvious to all, but after all, it is underwater, and underwater has never been a special place for humans.
Even Monkey King is not good at swimming, let alone ordinary humans.
In addition, the opponent is the famous water buffalo, which is bound to make people worried.
Mandy and Keke are both great . One is a national champion, the other is a professional coach. They both know a lot about underwater creatures, but that doesn't mean they can fight those creatures.
Even if she wanted to go into the water to help Bifang, she would be unable to do anything. Instead, there was a possibility that Mandy would encounter the same situation as Niugang trevally, where she would be knocked unconscious at the first sight and become a huge burden.
"It's been ten minutes. Nothing unexpected will happen, right?"
"It's not like we didn't bring our oxygen tanks. Let's wait a little longer."
"Hey, here they come!" Mandy pointed at the sea and shouted suddenly.
The calm sea surface suddenly broke through a wave, and Bifang stood on the shallow sea with a spear on his shoulder. A huge fish almost as tall as a person was hanging on the tip of the spear, and a mixture of blood and sea water was dripping down.
Bifang took off his goggles, closed the oxygen valve, and took a deep breath of the fresh air from the coast. The thick salty wind filled his lungs, and he felt the long-lost refreshment.
The tail fin of the Niugang twitched subconsciously, and Bifang threw it to the ground and stabbed it again.
Mandy and Keke waded over quickly and looked in amazement at the Niugang trevally whose body was half covered by sea water.
Mandy waved her hands and yelled, "WTF, I thought you were going to beat it away, but you just killed it?"
Bifang waved his hand, found a few nodes on the Niugang croaker, and stabbed it with a spear.
"What are you doing? Isn't it dead?" Mandy was surprised. Now he was very excited.
It’s one thing to see it on TV, but it’s another to experience it yourself, especially when you’re a witness to how powerful the Niugang trevally is.
After Bifang stabbed the fish with a few spears, blood from the Niugang croaker gushed out from the holes.
"Few people buy Niugang trevally, not only because the meat is not good, but also because it contains a lot of toxins."
"This guy mainly feeds on crustaceans, arthropods, fish and waterfowl. Some of the crabs, shrimps, snails and marine fish that it likes to eat contain natural biotoxins that will accumulate in the blood of the Niugang trevally. Therefore, bleeding and detoxification are necessary immediately after catching it to prevent accidents after eating it."
Only some experienced sea fishing players know these key points. Many novices are completely unaware of them. Even amateurs like Ke Ke are not aware of such things.
No wonder the last time I went sea fishing, I saw someone piercing a few holes in the Niugang trevally he caught. At that time, Keke thought the man was too tired and was taking it out on it.
Bifang and Keke dragged a 70-kilogram Niugang trevally to the shore.
"Eat, you want to eat it?"
Bifang nodded: "I want to try it."
Even though it didn't taste good, Bifang knew that. He himself had never tasted it. Besides, he had fished it out himself, so there was no need to throw it away.
"How did you kill it?" Mandy and Keke were very curious.
Bifang shook his head again and told the two what had just happened underwater.
Mandy's eyes were shining, obviously excited to meet a fellow creature.
"I hope that the last attack can break the dolphins' good impression of humans. It would be best if they could run far away, leave when they see a fishing boat, and never come back here again." Bifang sighed.
The atmosphere suddenly fell silent.
Keke nodded silently. Isn't it sad to prevent dolphins from developing a liking for humans?
"Okay, don't think too much." Bifang held the two people's shoulders and looked up at the moon in the sky. "It should be around twelve o'clock now. We don't have much time. Hurry up and work!"
"Let's finish all this as soon as possible and tell the public all the truth. This is the purpose of our coming here!"
The black bear hunting season began on July 12. On the first night, Bifang, Mandy and Keke set up a camera position in the jungle.
Today is the second day of the hunting season, which is the evening of the 13th. We will try to set up all the underwater cameras by tonight.
There are many places on the mountain with good shooting angles, but we didn’t have time to install them.
In order to carry all these equipment, Richard and his team used a total of forty-three large boxes, which shows how heavy the task was for Bifang and the other two.
This is not just about moving things out and arranging them, but it requires placing them in appropriate places and at appropriate angles according to different conceptual features and disguises.
According to the information Bi Xiang learned from local fishermen on the first night, the dolphin fishing season will begin on July 15, which is the evening of the day after tomorrow.
A grand sacrifice is held in the evening to announce the start of the annual dolphin hunting season which lasts for more than half a year. On the morning of July 16, many fishing boats will leave the harbor and use sonar equipment to drive all the dolphins in the nearby waters to the Dolphin Bay which is surrounded by mountains on three sides.
Carry out mass killings.
They don't have much time left. Tonight, the night of the 14th, and the night of the 15th at most, there are three more chances and the massacre will begin.
Time waits for no one.
The three of them acted quickly. Mandy nervously put on the spare diving bottle and followed Bifang into the water.
Ten meters, twenty meters, thirty meters.
Bifang and Mandy quickly adapted to this process and dived deeper.
After crossing more than thirty meters, a completely different feeling arises.
Their whole bodies were different. The huge pressure of sea water slowly changed the body density of the two people until it reached a certain critical point.
Bifang felt his body sinking. The buoyancy could no longer completely offset the gravity. Under the drag of gravity, the two of them slowly fell towards the depths.
This is a feeling that a diving trainer can never bring you, magical and wonderful.
They were slowly pushed into the depths of the ocean.
There are three most important diving laws that any diver needs to remember:
Boyle's law.
Dalton's law.
Henry's law.
Sounds familiar, right?
That’s right, these are the three laws of gas circulation.
The vast majority of recreational divers use air or enriched air as their primary breathing gas. These scuba diving gas laws apply to all breathing gases. In more other diving areas, such as Bifang and Mandy's technical diving at this time, you may also encounter trimix or pure oxygen.
The first rule of scuba diving: Never hold your breath!
Corresponding to Boyle's law: for an ideal gas, when the temperature remains constant, the pressure and volume are inversely proportional.
Imagine the lungs as a balloon. We can inhale to blow it up, or exhale to let the air inside it out and make it shrink.
As we descend, the pressure rises, and with each breath the air inside the lungs is compressed, but the space in the lungs is filled again as we take a full breath.
The deeper you dive, the higher the pressure is, and more air is needed to fill it, so air consumption increases.
The pressure on a diver's lungs at depth causes them to require more energy to expand their lungs.
When breathing is done regularly, the "balloon" never expands too much.
The same is true for the next two laws.
The reason why deep diving is called technical diving is because it involves so many technical means.
This is a matter of balancing the lungs and qi.
Coincidentally, Bifang is well aware of this.
These abyssal worlds seemed to be completely separated from other places on Earth. They had been waiting there quietly for millions of years until Bifang's flashlight cast its first ray of light there.
A pressure-resistant infrared detector was installed forty meters away.
This is a military equipment and cannot be taken out of the country under normal circumstances. It was approved only after Bifang applied for it. Through infrared rays, it can better detect the activities of dolphins.
Above thirty meters, the sunlight can still barely shine through, but below thirty meters, it will be pitch black even in the daytime. Therefore, as they go further down, Bifang and others need to install detection devices instead of cameras.
Perhaps more than half of these devices are useless, but they must exist, just like there will be a large number of wasted shots in a movie shoot. Not every device can capture the perfect shot, but it must exist.
After loading, Bifang did not dive rashly. Instead, he turned on his flashlight and made a series of flash signals to Mandy.
After Mandy finished answering, he also shot out a flash, and Bifang responded.
After confirming that both of them were fine, Bifang adjusted the gas in the oxygen tank and continued to dive.
People usually define diving within a depth of 40 meters as recreational diving.
Why did you choose the number 40 meters?
Two reasons.
First, when diving at this depth, you can ascend directly to the surface in an emergency without worrying about serious safety issues.
Second, the partial pressure of air at sea level is one bar. At an oxygen partial pressure of 1.4 bar, the toxicity of oxygen will become increasingly greater. Oxygen poisoning may affect the diver's central nervous system and cause nerve spasms in the diver underwater.
This will directly affect the diver's ability to engage the regulator.
Similarly, when the partial pressure of nitrogen is around 30 meters and exceeds 3 bars, some divers will feel anesthetized, and this feeling worsens as the partial pressure increases.
This is Henry's law, which relates the solubility of a gas in a liquid to the surrounding pressure.
As the diving depth increases, more nitrogen accumulates in the human body.
These nitrogen gases will put the human body into a state similar to being drunk, commonly known as "nitrogen intoxication".
At a depth of less than 40 meters, the effects of nitrogen narcosis can be so strong that people lose their judgment and reaction ability, leading to safety accidents.
Many people don’t even realize that they are suffering from nitrogen incense. They feel very sober and even high, but they can’t even solve the basic math problem of one plus one equals two.
Just now, Bifang and Mandy were making sure each other was awake by giving each other a two-digit addition and subtraction math problem.
Because of this, people limit the depth of recreational diving to 40 meters. Diving beyond 40 meters enters the field of technical diving and industrial diving.
Troubles such as decompression sickness and nitrogen narcosis are all caused by nitrogen, but we cannot do without nitrogen because breathing pure oxygen directly is toxic.
Astronauts can breathe pure oxygen for several hours before a spacewalk without being affected by decompression sickness, but this is because the air pressure inside the space suit is lower than that inside the space station, which is equivalent to a decompression environment.
Pure oxygen toxicity is conditional - when the partial pressure of inhaled oxygen exceeds 0.3 bar (30 kPa), oxygen becomes toxic to cells.
There are things that astronauts can do in space that they cannot do underwater. Inhaling pure oxygen in a high-pressure environment underwater can cause oxygen poisoning.
The human body is so fragile.
Even more precisely, at a depth of more than 55 meters underwater, even breathing air will lead to oxygen poisoning, let alone breathing pure oxygen.
At this time, the oxygen cylinders behind Bifang and Mandy contained three gases: helium, oxygen, and nitrogen.
This is the so-called three-phase gas. The addition of helium reduces the content of oxygen and nitrogen. Just how to proportion the content is enough to give amateurs a headache.
Not only diving, but surfacing is even more troublesome. You need to stay at different depths for a sufficient amount of time in order to gradually expel excess nitrogen from the body.
The world record for technical diving was set by a man named Ahmed Gabr in 2014 - he dived to a depth of 332 meters.
It took Gabr only 14 minutes to descend to 332 meters, but 14 hours to surface.
Even though Bifang can now dive into a depth of 70 meters with his bare hands, this is based on the premise that he does not need to stay there for a long time and the changes in his body are not too drastic.
If he stayed too long, he would also need to obey the laws of physics.
50 meters underwater.
Bifang's body enters the second stage, and the capillaries in the lungs begin to become congested and hardened to protect the chest cavity from being damaged by water pressure.
The pressure is getting greater and greater. If an ordinary person enters such a stressful environment in an instant without any preparation, he will surely die.
A long time passed, until we were 80 meters underwater.
Eighty meters, a number that makes people feel suffocated, but the more they struggle, the more dangerous it becomes.
Here, you can only rely on spiritual and psychological strength to overcome it, tell yourself to follow nature, and only by completely relaxing can you turn harm into protection.
In the dark world, far away from light and humans, accompanied only by coldness and loneliness, Bifang seemed to have turned into a tiny drop of water, floating quietly in the ocean.
As the last piece of equipment was installed, Mandy and Bifang both breathed a sigh of relief.
Plan completed!
