Due to the special environment of marine archeology, scientific researchers have modified the underground metal detector so that it can also function underwater, but the effect is much worse than when used on the ground.
In fact, this thing looks very simple. It is just the top of a metal rod, forming a metal coil. When surveying the seabed, as long as there is metal underneath, they can hear the alarm sound in the earphones.
Of course, the error of this thing on the ground is about 20%, and the error is even greater when it reaches the bottom of the sea. It is not as magical as Zhuang Rui imagined.
After hearing Zhuang Rui's question, a diver retorted: "Mr. Zhuang, we have detected an area of more than thirty meters and found nothing. Maybe the silt layer is too deep?"
More than half a century has passed since the sinking of the "Awa Maru". After sixty or seventy years of seawater erosion, it is normal for silt to accumulate more than ten meters deep. The diver's words made everyone nod slightly.
"Uh... I don't mean to blame you. I mean, after all, it is difficult to grasp the specific location where the Awa Maru sank. The survey is now based on the location where it was last salvaged. I think you can expand the scope of the survey.
If you expand a little bit, you might find something..."
Zhuang Rui couldn't tell the first location where the gold was hidden. It was more than two hundred meters away from the salvage ship, right? He couldn't explain it and could only suggest expanding the divers' search range.
"Oh, if I had known better, I would have been more prepared and brought the side sonar device..."
Professor Meng sighed, turned to look at Zhuang Rui, and said: "Xiao Zhuang, your ship is so advanced and is used for professional salvage. Is it possible that it is not equipped with a side sonar system?"
"Teacher, it really doesn't exist. Otherwise, the Maritime Safety Administration must have this object and call it over urgently, right?"
Zhuang Rui smiled bitterly when he heard this. The side sonar system that Professor Meng mentioned is also called "seabed scanning sonar". It is designed and manufactured using the principle of ultrasonic wave propagation and reflection in water to detect seabed landforms.
of instrumentation.
Seabed scanning sonar consists of transmitters, transducers, receivers, controllers and recorders.
When a transducer installed on the probe converts the supplied electrical energy into sound energy and transmits sound waves of a certain frequency to the seafloor, the sound waves rapidly propagate into the seawater at a speed of 1,500 meters per second and move toward
Scattering in a predetermined direction.
When the sound waves reach the seabed, because the topography of the seabed is undulating and diverse, some of the sound waves correspond to the shape, nature and height distance of the reflection point, forming wave speeds of different strengths and weaknesses that are reflected back in sequence.
The improved seabed scanning sonar can have special responses to gold and silver substances, so this device is not only limited to marine landform detection, but can also be used in deep-sea archeology.
But Zhuang Rui has such eyes. He has never thought about not being able to find objects in the sea, so he has never thought of installing a seabed scanning sonar system on his luxury salvage ship.
Of course, this device is not omnipotent. It only reacts to relatively dense gold and silver substances. If the wreckage of the Awa Maru shipwreck is severely decomposed, even if it is equipped with a seabed scanning sonar, it will be useless.
"There is some in the bureau, but it will take at least two days to transport it from Beijing..."
Director Wu agreed with Zhuang Rui's opinion. Anyway, all the costs of the salvage would be borne by Zhuang Rui. He didn't care if he stayed for a few more days.
Zhuang Rui nodded and said: "Teacher, Director Wu, I think we should use the metal detector to detect while waiting for the sonar device. We can't be idle, right?"
Zhuang Rui's words made the divers of the Maritime Safety Bureau deeply resentful. Diving into the sea water of tens of meters is an extremely physically demanding task, and long-term diving will also have an impact on the chest and lung function, and it is very easy to
produce some occupational diseases.
Of course these brothers are not happy about using high technology and enslaving divers like them. However, Zhuang Rui is the deputy commander-in-chief of this salvage operation. Even if he is named, it is not something that the staff can object to.
"Well, what Xiaozhuang said makes sense. Let's expand the search scope and try to find something as soon as possible..."
Speaking in an official tone, Director Wu was obviously very familiar with the business, and he didn't want him to get into trouble anyway, so he nodded and agreed with Zhuang Rui's opinion.
Professor Meng returned to the salvage site more than 20 years ago. Naturally, he wanted to find the wreckage of the Awa Maru as soon as possible. He also nodded and said, "Thank you for your hard work. The coordinates from more than 20 years ago will definitely change. Everyone will
The search range should be expanded to about a hundred meters..."
Several leaders spoke. Although the divers were reluctant, they put on their diving suits again. But what shocked them was that Zhuang Rui actually asked for a set of diving equipment and put them on.
Professor Meng also saw Zhuang Rui's behavior at this time, and asked in surprise: "Xiao Zhuang, what are you... doing?"
Diving requires professional training, especially deep-sea diving. The water pressure below tens of meters is enough to kill someone without diving experience, so Professor Meng was very puzzled by Zhuang Rui's behavior.
"Teacher, I have experience in salvaging sunken ships from the Song Dynasty. I have a good understanding of the behavior of ships on the seabed. Let's go down and have a look..." Zhuang Rui made an excuse casually.
"Hey, Xiaozhuang, this kind of diving can only be carried out by professionals. Don't fool around..."
Although Zhuang Rui's courage is commendable and his behavior is worthy of praise, this is no joke, especially as the seabed is so unpredictable that he may encounter danger at any time.
"Teacher, it's okay. When I was looking for the pirate island, I could dive down to a depth of 20 to 30 meters with my bare hands. This sea area is only more than 40 meters, so there is no problem at all..."
Zhuang Rui laughed when he heard this. The current record for freehand diving seems to be 105 meters. With Zhuang Rui's physique, he dare not exceed this record, but the depth is only thirty or forty meters, which is not challenging at all for Zhuang Rui.
What's more, there are also decompression diving suits and a series of diving equipment. Zhuang Rui really wants to go to the bottom of the sea to see the scenery. What's more, if he doesn't go down, he may have to wait at sea for two days in vain.
"Okay, then be careful. If you feel any discomfort at the bottom of the sea, come back immediately..."
Professor Meng thought of what Zhuang Rui had done at sea, and had no doubts about his words. He didn't say anything more at the moment. After all, having someone with rich archaeological experience accompanying him in the survey would increase the chance of finding the wreckage.
Seeing Zhuang Rui, the deputy commander in chief, diving with them for survey, the divers had no complaints. After Zhuang Rui put on his diving suit, they taught Zhuang Rui how to use the propeller.
What they used was a single-person thruster, which could speed up the dive. This object was easy to operate. After Zhuang Rui listened to it once, he understood it.
"Husband, you have to be careful..."
Qin Xuanbing also heard the news that Zhuang Rui was going to the sea, and ran over with Fang Fangyuan. The storm that raged in the middle of the night yesterday really made Qin Xuanbing a little scared.
"Ahem, what's the big deal? Wife, the scenery at the bottom of the sea is very beautiful. How about... let's go down together?"
Zhuang Rui's nonchalant words immediately caused glasses to fall all over the deck. Just now, I thought Zhuang Rui had noble sentiments, but who knew that this guy was going to the bottom of the sea for a tour? And it wasn't enough to go by himself, he actually wanted to take his wife with him.
?
"You brat, you're joking right now..." Professor Meng scolded Zhuang Rui with a smile, and everyone finally realized what Zhuang Rui was doing to prevent his wife from worrying?
Knowing that Zhuang Rui was joking, Qin Xuanbing was not so nervous. After giving Zhuang Rui a few more instructions, she watched Zhuang Rui go down the spiral staircase.
In fact, when it comes to the scenery, this sea area close to the coastline is really not that good. Compared with the pirate island back then, it is simply a world of difference. In terms of water quality alone, there is no comparison between the two.
Taking the propeller down to the sea water, Zhuang Rui grabbed the handle on the propeller and started it. The propeller at the tail of the propeller started to rotate, taking Zhuang Rui to the bottom of the sea.
There was an oxygen bottle on his back, an oxygen mask on his face, and a walkie-talkie in his ear. Except for a slight chill when he went down to a depth of more than 20 meters, Zhuang Rui did not show any discomfort. This also made the people who were guarding the monitor on the boat
Everyone breathed a sigh of relief.
From the ocean surface to a depth of 200 meters, it is called the upper ocean layer in terminology. In this range, sunlight can penetrate the sea water. The water layer from 200 meters to 1000 meters is called the middle layer of the ocean. The sunlight here cannot
All the light passes through the sea water, the light is very weak, and the sea water is a gray-blue color.
The water layer from 1000 meters to 4000 meters is called the semi-abyssal layer. There is no sunlight here, and it is a dark world.
Zhuang Rui and others only dived to a depth of forty meters. After reaching the bottom of the sea, they could clearly see the surface of the seabed even without turning on the strong light. However, out of caution, as soon as they reached the bottom of the sea, they
Turned on the headlights on the thruster.
"Each person is responsible for a range of fifty meters. When you feel that there is not enough oxygen, dive immediately..."
After seeing Zhuang Rui and other five people descending to the seabed, the diving director monitoring above issued orders to several people. The oxygen consumption in the compressed air bottles carried by each person was determined based on various factors such as water pressure, depth, etc.
Although several people use large bottles, they can only last for about an hour at the bottom of the sea at 40 meters. And when the oxygen is exhausted at the bottom of the sea, it is self-evident to take over.
"clear……"
After Zhuang Rui was the first to agree, he gestured to the others to indicate the direction in which he wanted to conduct the survey, then used the propeller to turn and swim towards his target.
With the help of the propeller, Zhuang Rui was saved a lot of time. After only a few minutes, he arrived about 200 meters away from the cruise ship.
