When diving, there is a different probability of encountering sea currents depending on the dive site.

As the name suggests, the descendant is a downward current, which can be seen from the bubbles exhaled from the mouths of the three people, the bubbles that were originally rising suddenly scattered around them in a ring, and then began to float downward, and the two turtles not far away shrank back into the rock crevices when they saw the bad situation, and at the same time the vision of the three began to become cloudy.

But fortunately, except for Zhang Heng, the other two are not novices, including Han Lu, it is not the first time they have encountered the current, so they will not be as flustered as a beginner, Han Lu is on the edge of the stone wall, and when he saw this, he immediately attached his body to the stone wall, holding the stone wall like a gecko.

And Nelly turned on the flashlight she carried, shone on the big rock closest to Zhang Heng, and motioned for Zhang Heng to go over, and she herself swam there, the descent speed of the two was not fast, which showed that the current they encountered was not strong, which made Nelly breathe a sigh of relief, and Han Lu and Zhang Heng were also very calm.

The most dangerous thing under the water is to fall into a panic, not only can not solve any problems, but the random struggle will accelerate the consumption of oxygen, and the wrong operation is likely to bring more trouble, Han Lu because she has enough diving experience Nelly is not too worried, what she is really worried about is Zhang Heng on the other side, especially the latter has just asked to rise, and as a result, he encountered the current in a blink of an eye.

But fortunately, so far, Zhang Heng has not shown any panic, and swam to the edge of the rock with Neli.

About a minute and a half, Nelli felt that the current had become smaller, so she gestured and asked Zhang Heng how much gas he still had.

Zhang Heng glanced at the residual pressure gauge, which showed that he still had about 120bar of gas, and the three of them did not stay underwater for a long time, and they basically moved at a depth of about 25 meters, and they did not dive too deep, so the gas consumption in the gas cylinder was not much, and it was still far from the warning line.

But since Zhang Heng has decided to ascend, of course, as a dive guide, Nelly has no reason to continue to insist on diving, but before ascending, the two still need to meet Han Lu at the stone wall.

Unlike the relatively clear water, the visibility in the water has become very low due to the influence of the currents, which bring up a lot of sediment and impurities. Nelly turned on her flashlight again, but I don't know if it was due to the lack of power, the flashlight in her hand flashed several times this time before it gradually stabilized.

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.

Nelle blinked, as if she couldn't believe what she was seeing, because when the descent came, Han Lu was the first to find a place where her body could be fixed, and seeing that her condition at that time was obviously out of danger, and then the three of them were separated for less than two minutes, and Han Lu had no reason to leave this position in such a short time.

Nelly then turned the flashlight to other directions nearby, searching for the figure of Han Lu, but there was no receipt, and at this moment, Nelly saw Zhang Heng gesturing to her and pointed to the top of her head.

Neli thought that Zhang Heng had discovered Han Lu's location, but when she looked up, she saw a strange scene that she had never seen in her years of diving experience, and saw that the sea water above their heads was constantly turning red at a speed visible to the naked eye.

Is this red tide?

Nelly lives by the sea, although she has never seen red tides with her own eyes, but she is no stranger to this natural phenomenon, red tides are generally caused by some phytoplankton, bacteria or protozoa in the seawater in a short period of explosive reproduction or high aggregation, which will make the sea water discolored, and it is also very harmful to the environment.

However, this area is a famous diving site on Yonaguni Island, and the residents of the island have always paid great attention to the ecological environment, so for so many years, there has never been a red tide in the nearby sea, and the red tide generally affects the upper layer of the water, but Nelly found that the red above her head was rapidly approaching them.

Soon the two of them were also filled with red sea water, the color of these seawater is actually very close to human blood, it is very infiltrating to be in it, and the most important thing is that they will further reduce visibility, now Neli can only see less than two meters in front of her, and even Zhang Heng's figure on the side has become faint.

Even with Neli's rich diving experience, she can't help but be a little anxious now, mainly because this strange "red tide" appeared neither early nor late, just at the pass where they were looking for Han Lu, which made the next search work suddenly difficult.

Neli wanted to take Zhang Heng up first and then come back to find Han Lu by herself, because Zhang Heng had already made a request to her to ascend before the downflow appeared, but it took time for divers to ascend, because the pressure at different depths is different, and when the diver is at a deeper depth, nitrogen will dissolve into the blood.

At this time, the main thing is the danger of drunken nitrogen mentioned earlier, at this time the nitrogen is dissolved in the blood, and if the pressure decreases rapidly, the nitrogen dissolved in the blood will precipitate out and cause blood clots, which will make the diver suffer from diving sickness, and the heavy will directly burst the lungs.

Therefore, there needs to be a safe stop time when ascending from underwater, and it will take seven minutes for Nelle to send Zhang Heng to the boat and come back at the earliest, not to mention whether she can get back to her current position in this blood-red sea water, it is difficult to say if Han Lu is still nearby at that time, and the remaining gas in her gas cylinder may not be enough to support her to search for too long.

If in normal times, of course, Nelly could choose to take Zhang Heng to look for Han Lu together, but because of the influence of this strange red tide, as long as the two are separated a little distance, they may not be able to see each other, and in this harsh environment, Nelly is not confident that she can take care of Zhang Heng when looking for Han Lu.

Han Lu has already disappeared, don't lose Zhang Heng when the time comes.

After a short period of thought, Neli still decided to take Zhang Heng up first, because she still had luck in her heart, maybe Han Lu had already returned to the boat before them, and they would be able to see each other when they surfaced, and to tell the truth, even if she took Zhang Heng to risk to find Han Lu now, it was actually just luck.

But just as Nelle was about to take Zhang Heng up with her, there seemed to be a glimpse of a black shadow flashing past her in the afterglow of her left eye.

Could that be Han Lu? There was a glimmer of hope in Nelly's heart, and although the dark shadow passed quickly, she still saw a rough outline, which did look like a person in a diving suit.