A few fighter planes were parked above, one fighter plane slowly moved, slowly drove onto the runway, there were people on the deck to guide the plane to move, a piercing whistling sound came, the fighter plane took off into the air and began to soar in the blue sky.

"This is an aircraft carrier training ship, we have prepared for the construction of an aircraft carrier fleet, fighter planes are training day and night, once our country builds a domestic aircraft carrier, we can directly carry fighter aircraft to sea." Shark said.

"Oh, if only I could fly a fighter on an aircraft carrier." The pilot said regretfully.

"Pilot, you still regret it, I haven't even flown a plane." Said the engineer.

"You, we're not at the same level at all." The pilot quipped.

Da Jiefang drove to a swimming pool next to it and slowly slowed down, as soon as the car stopped, everyone jumped out of the car, because they were too interested in today's equipment, especially the oxygen tank, which means that diving training is about to begin, the water goggle, just covering the eyes and nose, it is difficult to breathe out after wearing it, and what BCD (buoyancy adjustment device), respirator (Reg, including the first head, the second head, the spare second head), the instrument, the dive computer, the flashlight, the elephant pull. I don't know what I'm used for.

"Take a break, stand upright, look to the right, look forward." After Gao Jian formed the team, he said: "The shark is responsible for everyone's training, shark." ”

"Here." The shark walked to the front of the queue: "Let's first carry out the training of the first subject, called mask drainage, the one we wear on the head is called the mask, the mask is a tool to cover the eyes and nose when the "frogman" dives, and the mask is to ensure that the eyes can be opened normally and protect the nose from choking. However, when the "frogman" performs the task in the water, it may cause the mask to fall off or enter the water for various reasons, if the mask is not drained at this time, not only the eyes can not be opened normally, but also the nose may choke on the dangerous situation, so we must first carry out the mask drainage training, if the mask drainage training is not completed, it can not be transferred to the next stage of training. The next stage of training is diving training based on mastering the mask drainage. Let's watch me explain and demonstrate. "The shark started to show everyone how to drain the mask.

Don't look at the mask drainage sounds very simple, but it is not easy to do it, the shark deliberately filled the mask with water for everyone to wear, let everyone try to drain the water, Zhang Shun put it on and inhaled it with his nose, and choked at once, and tried twice in a row without success, the shark patiently knew how Zhang Shun drained, after trying more than ten times, Zhang Shun barely completed the mask drainage, not only Zhang Shun, other teammates were not so lucky, they all tried several times in a row to master the essentials of the mask drainage.

Mask drainage is only the most basic training of diving, the real test has just begun, because those who can't name the equipment have to learn to use, a simple mask drainage is so difficult, the rest can be imagined, seeing that everyone has mastered the essentials of mask drainage, the shark ordered everyone: "Carry an oxygen cylinder." ”

Everyone heard the order, hurriedly put the oxygen cylinder on their backs, everyone knew what they were going to do next, the oxygen cylinders should be fixed after the back, and everyone's hands couldn't help shaking when they tied the rope......

Seeing that everyone fixed the oxygen cylinder, the shark said to everyone seriously: "Diving is actually an extremely dangerous training subject, our frogman brigade has been established for ten years, drowning happens every year, at least fifteen frogmen have become martyrs, everyone must put safety first, first of all, the water should be slow, let the body slowly adapt to the water pressure, and secondly, we must always pay attention to the change of the oxygen cylinder pressure gauge, absolutely not cut off oxygen underwater, if it is in the deep sea diving, but also to prevent underwater undercurrent, Beginners should pay special attention to the fact that when coming out of the deep sea, it must be slow, so that the pressure in the body and the pressure outside the body are gradually balanced, if the water is too fast, you will feel ear pain, and when the ear pressure balance problem is serious, it will also lead to injury to the eardrum and ear drum, if the speed of rise exceeds the speed of free rise, it will be very terrible, and the consequences are very terrible, that is, the volume of gas in the lungs suddenly expands, causing the lungs to burst. ”

"Blowing up lungs?" Listening to the shark's words, everyone couldn't help but gasp.

"Burst lungs are a sudden release of physical phenomena because of the sudden decrease in pressure in the lungs, just like the firecrackers we set off when we were children, "bang" is over with a sound, even the fish in the sea are not spared, we often see some fish with bursting abdomen on the sea, all of them burst lungs to death. In addition to the more heroic lung explosion, there is also a little gentle, that is, the legendary decompression sickness, every new diver should smell the color change, because at the beginning of training, new divers will have different degrees of decompression sickness, it usually occurs within 2-48 hours after surfacing, decompression sickness includes many different symptoms, what joint pain, limb numbness, or large red spots on the skin, may be a sign of decompression sickness, serious will leave decompression sickness sequelae, if you suffer from decompression sickness sequelaeWe will not be able to dive again for the rest of our lives, so we have to be extra careful to prevent the occurrence of decompression sickness, and we will start to enter the water. "The shark's words are a bit alarmist and suspicious.

I thought I would be able to become a frogman soon, but I didn't expect the road to become a frogman so tortuous, in order to be able to become a frogman smoothly, everyone went out, and was extra careful when entering the water, don't have a decompression sequelae, let alone burst your lungs.

The shark continued: "As a frog man, in addition to taking the risk of physical injury, the most important thing is to endure loneliness, because the vision below five meters is more blurry, and there is a sense of oppression in breathing, below fifteen meters, the light can no longer be reached, and the eyes will be dim, everyone will obviously feel the pressure in the chest, and it will become difficult to breathe, in this environment, everyone will have a sense of fear, so we should dive more than fifteen meters for the first time, and then dive to the depth after slowly adapting to it, Our deep-water diving training ground has a depth of 80 meters, and there are some plastic balls tied to the bottom of the water, if you can dive to the bottom of the sea, you can take a plastic ball, which means that you have completely become a qualified frogman, the first dive, I do not advocate that you dive to the bottom, you can dive to a depth of 50 meters, I bet that none of you will dive to the bottom of the water, I don't believe that you can try it when you dive next time, now everyone is ready to go into the water in pairs, pay attention, each group of team members can not leave their teammates, If one person does not dive, the other must stop. ”

Zhang Wei and Zhang Shun are a group, for the sake of safety, Zhang Wei repeatedly explained the matters that Zhang Shun should pay attention to, Zhang Shun nodded again and again, the two of them grabbed the oxygen tube with their mouths and held hands and dived into the water, before, the mouth was used to eat, but now it is used to inhale, the nose used to be used to breathe air, but now it is useless, if there is water in the mask, you need to use the nose to suck the water out, the function has changed, and it is really a little uncomfortable to slam the water, the two of them held hands in the water for a while to get used to it, and then it began to sink slowly, Sure enough, as the shark said, at a depth of five meters, the two were able to see each other clearly, as the depth deepened, the vision gradually blurred, and after a while, the two fell into darkness, the body seemed to be wrapped in a layer of plastic film, the ear drum was slightly painful, and the breathing was also rapid, Zhang Wei wanted to stop and rest for a while, but he didn't expect Zhang Shun to pull him down vigorously, the water pressure seemed to him to be non-existent, Zhang Wei couldn't help but secretly admire.

After diving down for a while, Zhang Wei couldn't help it, he felt like a big stone in his chest, and hurriedly balanced the pressure inside and outside his body, so he felt a little comfortable, look at Zhang Shun, there was no intention to stop, Zhang Wei had to passively follow Zhang Shun and dive down.

In the monitoring room, the shark and Gao Jian are staring at the screen, most of the team members have exceeded the depth of 30 meters, indicating that everyone has passed the first dive, most of the team members have slowed down the speed of diving, and some have stopped, it seems that they are ready to dive upward, but what makes the shark feel incredible is that Zhang Wei and Zhang Shun have dived to a depth of 50 meters, although the speed of the dive is slower than before, they have no sign of stopping, and they are still approaching 60 meters.

The shark felt a burst of relief in his heart, it seemed that these team members did not disappoint him, the first dive exceeded fifty meters, remembering that when he dived for the first time, he only dived to forty-nine meters and could not dive anymore, he watched with great interest Zhang Wei and Zhang Shun move into the depths.

It's more than sixty meters, the shark's relief just now began to turn into worry, Zhang Wei and Zhang Shun are both novices, if they continue to dive, they have no experience in how to deal with emergencies, the shark hopes that the two of them will stop diving, but Zhang Wei and Zhang Shun have no intention of stopping at all.

Zhang Wei and Zhang Shun were already close to seventy meters, and the shark's face couldn't help but ooze sweat, and he shouted into the microphone: "Zhang Wei, Zhang Wei, please stop and don't dive down again." ”

When Zhang Wei heard the shark calling, he squeezed Zhang Shun's hand, meaning to ask him to stop, because he couldn't talk verbally in the water, and he couldn't see it, so he had to use his body touch to convey the message.

Because there was no communication in advance, Zhang Shun didn't understand what Zhang Wei meant, and he thought that Zhang Wei was encouraging him to continue diving, and dived harder to the depths.