Chapter 906 Red Tide?

When diving, there are different probabilities of encountering currents depending on the diving location.

Downwelling, as its name suggests, is a downward ocean current. This can be seen from the bubbles exhaled from the mouths of the three people. The bubbles that were originally rising suddenly spread around them in a ring shape, and then began to float downward, and The two turtles not far away saw that the situation was not good and shrank back into the rock crevice. At the same time, the vision of the three people began to become turbid.

Fortunately, except for Zhang Heng, the other two people were not novices. This was not the first time for them, including Han Lu, to encounter the current, so they were not as panicked as beginners. Han Lu was at the edge of the stone wall and immediately rushed to the scene. His body was pressed against the stone wall, clinging to it like a gecko.

Nili turned on her portable flashlight and shined a light on the big rock closest to Zhang Heng. She signaled Zhang Heng to go there, and she swam there herself. The two of them did not descend very fast, which meant that they encountered The current was not too strong, which made Nili relieved. In addition, Han Lu and Zhang Heng also behaved calmly.

The most dangerous thing underwater is to fall into panic. Not only can it not solve any problem, but random struggling will accelerate the consumption of oxygen, and wrong operations are likely to cause even greater trouble. Han Lu has enough diving experience Nili wasn't too worried yet. What she was really worried about was Zhang Heng on the other side, especially when the latter just requested to ascend, only to encounter a current in the blink of an eye.

But fortunately, Zhang Heng didn't show any signs of panic so far, and swam to the rock with Nelly.

About a minute and a half later, Nili felt that the current had become smaller, so she gestured to ask Zhang Heng how much energy he still had.

Zhang Heng glanced at the residual pressure gauge, which showed that he still had about 120 bar of gas. The three of them had not been underwater for a long time, and they were mostly active at a depth of about 25 meters. They did not dive too deep. Therefore, the gas in the cylinder is not consumed much, and it is still far from the warning line.

But now that Zhang Heng has decided to ascend, Nili, as a diving guide, of course has no reason to continue diving. However, before ascending, the two of them still need to meet Han Lu at the stone wall.

Different from the relatively clear water before, the visibility in the water became very low due to the influence of ocean currents, which brought up a lot of sediment and impurities. Nelly turned on her flashlight again, but whether it was due to insufficient power, the flashlight in her hand flashed several times before gradually stabilizing.

However, when Nelly moved the flashlight towards the rock wall where Han Lu was, she was shocked to find that there was no trace of the latter there.

Nili blinked her eyes, as if she couldn't believe what she saw before her eyes, because Han Lu was the first to find a place to fix her body when the downflow came, and judging from her condition at the time, she had obviously escaped. It was dangerous. The three of them were separated for less than two minutes. There was no reason for Han Lu to leave this position in such a short period of time.

Nili then turned the flashlight to other nearby directions, looking for the figure of Han Lu, but there was no receipt. And at this time, Nili saw Zhang Heng gesturing to her and pointing to the top of her head.

Nili thought that Zhang Heng had discovered Han Lu's whereabouts, but when she raised her head, she saw a strange sight that she had never seen in all her years of diving experience. She saw that the sea water above their heads was moving at a speed visible to the naked eye. Keep turning red.

Is this red tide?

Nelly lives at the seaside. Although she has never seen a red tide with her own eyes, she is familiar with this natural phenomenon. Red tides are usually caused by the explosive reproduction of some phytoplankton, bacteria or protozoa in the seawater in a short period of time or Caused by high aggregation, it will discolor the seawater and cause great harm to the environment.

However, this sea area is a famous diving spot on Yonaguni Island. The residents of the island have always attached great importance to the ecological environment. Over the years, red tides have never occurred in the nearby sea areas, and red tides generally affect the upper seawater. However, Nelly discovered that The red patch above their heads was quickly approaching them.

Soon the two people were surrounded by red seawater. The color of this seawater was actually very close to human blood. It was very permeable to be in it, and the most important thing was that they would further reduce the visibility. Now Ni Li could only see less than two meters in front of her, and even Zhang Heng's figure became indistinct.

Even with Nelly's rich diving experience, she couldn't help but feel a little anxious now, mainly because this strange "red tide" appeared neither early nor late, just at the point where they were looking for Han Lu, making the subsequent search impossible. Work suddenly became difficult.

Nili wanted to take Zhang Heng up first and then come back to look for Han Lu, because Zhang Heng had already asked her to ascend before the downwelling occurred. However, it takes time for divers to ascend because the pressure at different depths is different. When a diver At greater depths, nitrogen dissolves into the blood.

At this time, it is mainly due to the danger of drunken nitrogen mentioned before. At this time, nitrogen is dissolved in the blood. If the pressure decreases rapidly, the nitrogen dissolved in the blood will precipitate and cause thrombus, which may even cause blood clots. Divers suffer from diving sickness, which can lead to lung explosion.

Therefore, there needs to be a safety stop when rising from the water. It will take seven minutes at the fastest for Nelly to put Zhang Heng on the boat and come back, not to mention whether she can get back in the blood-red water as she wishes. At the current location, it was hard to say whether Han Lu was still nearby at that time. In addition, the remaining gas in her cylinder may not be enough to support her search for a long time.

In normal times, Nili could of course choose to take Zhang Heng to look for Han Lu, but due to the influence of this strange red tide, the two of them might not be able to see each other as long as they were separated by a little distance. In this bad situation, Under the circumstances, Nili was not confident that she could take care of Zhang Heng while looking for Han Lu.

Han Lu has already disappeared. Don't lose Zhang Heng too.

After a short period of thinking, Nili decided to take Zhang Heng up first, because she still had some luck in her heart. Maybe Han Lu had returned to the ship before them, and they would be able to see each other when they surfaced. , and to be honest, even if she takes Zhang Heng to take the risk to find Han Lu now, it is actually just a chance.

But just when Nili was about to take Zhang Heng up with her, she seemed to catch a glimpse of some dark shadow flashing past her in the corner of her left eye.

Could that be Han Lu? A glimmer of hope arose in Nelly's heart. Although the black shadow just passed quickly, she could still see the general outline, which indeed looked like a person wearing a diving suit.