Heavy rain has been falling for a night, thunder and lightning have been flashing, and the storm has been fighting against the trees on the island, pulling at the branches and leaves, trying to uproot the big trees.

The rain did not stop until seven or eight o'clock the next day.

The clouds dissipated and the sun showed its head.

Ye Kai walked on the ground, the sun was still hot, this rain did not have the slightest cooling effect, but made the originally hot and humid weather become stuffy, this situation is estimated to last all day today.

Today I have to travel to Tinian Island to take the diving certification exam.

Tinian is no longer part of Saipan, but is another city of the Commonwealth of the Northern Mariana Islands. But it's not far from Saipan, and the view from the sea is empty, and you can even see it faintly when the weather is good.

Although you can play deep diving everywhere on Saipan, after all, it is a group of student rookies, and you are not afraid of 10,000, but you are afraid of what happens, so the risk factor must be reduced to 0 on the exam occasion.

The airfare is $25.

When you buy, the conductor will ask you how much you weigh and how much you want to bring, and then assign you a position, from 1-7 from heavy to light.

When he saw the plane, Ye Kai was really stunned: "This kind of plane is still used by people?"

He originally thought it was flying by helicopter, but he never expected it to be the kind of plane during World War II, which flew by the air generated by the rotation of the propeller in front.

I thought that only such a plane would be used in movies, suitable for parking in museums to be watched, but I didn't expect it to be in 2019, and it was still in service?

Although it looks scary, the flight process is quite stable.

The plane did not fly high, and looking out the window, the scenery was similar to that of a towing parachute. But listening to the roar of the machine and the sound of the propeller turning, Ye Kai had a sense of absurdity that had traveled through the times.

Arrive at the test venue on time.

The exam involves three rounds of diving, scored by the instructor, and finally a 300-meter dive to get the certificate.

The three hundred meters of the exam were already a small problem for Ye Kai. Yesterday, he spent more than half an hour diving in the water before he came ashore, and 300 meters is a matter of minutes.

This exam can be said to be easy, and it is effortless to get a diving certificate, and it is AOW level.

Tinian Island is home to many World War II facilities, such as the remains of a Japanese communications station or a suicide cliff. Ye Kai felt that the people of the island country were not generally enthusiastic about suicide.

There are spots everywhere where they committed suicide, Saipan has it, Tinian has it.

In addition to this, Tinian has a large modern luxury casino hotel that charges more than the Clear Springs Hotel. After strolling in the afternoon, Ye Kai took a small plane back to Saipan.

Diving in the Blue Cave is the purpose of Ye Kai to learn to dive, and although it is not as attractive to him as before, it is still worth visiting. Located in the northeast corner of Saipan, it is the most famous and difficult dive site in Saipan.

Ye Kai thinks he is a diver who has seen the world, but he has been diving under the sea for half an hour, and he has touched sharks, and it is not a piece of cake to dive into the Pacific Ocean outside from the blue hole?

There are a lot of tourists here, but basically they come here to snorkel, and the underwater photographers who work here make money, and tourists line up to take pictures, which cost more than $600 a set.

Ye Kai was so jealous that his teeth were sore.

How much money do you have to make on this day?

went to the diving club and said that he was going to dive in the Blue Hole, and after showing his diving certificate, the person in charge of Ye Kai asked, "How many bottles of oxygen have you used?"

"Six Bottles ......"

All of them are used during training, and a whole bottle is consumed in the sea.

Just like when someone asks you how many hours you play, in the diving world, proficiency is directly proportional to how many oxygen cylinders are consumed.

It is said that it is an oxygen cylinder, but it is filled with compressed air, just to understand the image, most people call the bottle an oxygen cylinder.

"Is it okay to have six bottles, so much, and we can get two people with you?" he said.

Ye Kai was also afraid of danger, so he agreed.

It's definitely not free, otherwise why would people go into the water to protect you?But this cost Ye Kai felt acceptable, he wanted to see why the Blue Hole was rated as the second best cave diving in the world.

After putting on a diving suit at the club, Ye Kai and two divers came to the Blue Cave together.

No matter what month of the year, the number of visitors to the Blue Grotto is steady, and whenever you come here, there will always be a lot of people taking pictures or diving.

From the shore, the water of the Blue Cave is hidden under the stones, and there are more than a hundred steps to get to the water.

There is only one way to get into the water, and that is to jump off a rock more than a meter above the water, which is the simplest and most practical way.

The two divers are people who often dive here, and after sorting out the equipment, they were the first to go into the water, Ye Kai waited for them to get out of the way before jumping down, and then two people came over to help Ye Kai carry the oxygen cylinder on his back.

That's the benefit of spending money, thousands of dollars, more expensive than these people taking art photos.

The movements of several people attracted a lot of tourists swimming on the surface of the water, and they looked curiously at the three people who were checking their equipment.

Most of the people here are snorkeling or freediving, and only professional divers can go to the Blue Grotto, and most of the people who come to visit are not licensed.

The exam is too troublesome, not to mention expensive, and it will take a long time.

Finally, after checking the action camera and finding that it was working normally, Ye Kai bit the respirator and nodded to them. Then the three of them unloaded BCD's qi together and dived at the same time.

In another world, the ocean is not only isolated from the noisy sounds of tourists from the outside world, but also from the bright sun.

It's a deep blue underwater.

The underwater blue of the Blue Hole is known as the only electric blue in the world. This color is not seen anywhere else.

"It's beautiful. Ye Kai thought.

Unable to speak now, he gestured, "Let's go?"

The two divers gestured to him OK.

They don't know how many times they've swam here, and sometimes they even have to swim through here with people who don't know how to dive at all, which is called trouble.

The biggest challenge is balancing the pressure.

Tourists have never learned to dive systematically, and in addition to ear pressure, sometimes the mask will get into the water. Now that this tourist has his own diving certificate, this trip should be much easier.

In the distance of this deep blue ocean, there is a cave shaped like a giant mouth, this is where Ye Kai and the three of them will go in a while, from here they will swim all the way to the Pacific Ocean in the distance.

It's hard to see a larger underwater animal in this open water, and many of the marine life that live here swim into the depths of the Blue Hole or head straight to the Pacific Ocean.