Such incidents are not uncommon, and fishermen often encounter them. Year after year, day after day, the fishing nets on the seabed accumulate to many thick layers. When mixed with silt, they make the seabed environment increasingly worse, and even the receding tide cannot carry them away.
As for those disposable lunch boxes, Director Wu's explanation left Zhuang Rui and the others speechless. Apparently, these were things that the crew members on those ships would casually throw into the sea after finishing their meals during the trawling.
"Ahem, Director Wu, you should pay attention to publicizing this issue of marine environmental protection..."
Professor Meng was surprised to find that the culprits hindering the salvage operation were actually the fishermen along the coast, and he couldn't help but grumble a few words to the maritime bureau leader in front of him.
Upon hearing Professor Meng's question, Director Wu smiled wryly and said, "Well, Professor Meng, it's not that we don't value it, but... supervising it is just too difficult. We've already started banning fishing, so perhaps things will improve..."
"It really comes down to the quality of our people..."
Professor Meng shook his head, looked at Zhuang Rui, and said, "Zhuang, do you have any other ideas?"
Zhuang Rui was taken aback, scratched his head, and said, "Teacher, it doesn't really matter if there are fishing nets covering it. This metal detector can detect depths of seven or eight meters. If there really is shipwreck debris, it will still be able to find it..."
The metal detector that Zhuang Rui mentioned was the one that the divers had just taken off their backs. It's a diving metal detector specifically designed for ocean salvage. Originally used on the battlefield, it was used to dig out landmines.
Later, metal detectors were applied to battlefield archaeology, where most of the evidence is made of metal, such as musket bullets, cartridge cases, bullets, cannons and shells, shrapnel shells and swords, etc. The specific types of evidence depend on the historical period of the battle.
Therefore, the most important tool for battlefield archaeologists was a simple metal detector; however, in the decades that followed, metal detectors became the "weapons" of tomb raiders.
Chapter 1017 Finding a Needle in a Haystack (3)
Due to the unique environment of marine archaeology, researchers have modified underground metal detectors to enable them to function underwater, although the results are much less effective than when used on land.
Actually, this thing looks very simple. It's just a metal rod with a metal coil at the top. When it's pointed at the seabed for surveying, as long as there is metal underneath, they can hear an alarm sound in their headphones.
Of course, the error rate of this thing on land is about 20%, and the error rate is even greater on the seabed. It's not as magical as Zhuang Rui imagined.
Upon hearing Zhuang Rui's question, one of the divers retorted, "Mr. Zhuang, we've probed an area of over thirty meters and haven't found anything. Perhaps the silt layer is too deep?"
More than half a century has passed since the sinking of the "Awa Maru". After six or seven decades of seawater erosion, it is normal for silt to accumulate to a depth of more than ten meters. The diver's words made everyone nod slightly.
"Uh... I didn't mean to blame you. I meant that since the exact location of the Awa Maru's sinking is already very difficult to pinpoint, and we're currently conducting our survey based on the location from the last salvage operation, I think everyone could expand the survey area a bit more; perhaps we'll find something..."
Zhuang Rui couldn't very well reveal the location of the first hidden gold, which was more than 200 meters away from the salvage ship, could he? He couldn't explain it either, and could only suggest expanding the divers' search area.
"Sigh, I should have been more prepared and brought the side-mounted sonar..."
Professor Meng sighed, turned to Zhuang Rui, and said, "Zhuang, your ship is so advanced, and it's used for professional salvage, it must have a side-mounted sonar system, right?"
"Teacher, we really don't have any. Otherwise, how about this: the Maritime Safety Administration must have this item. Could we urgently request a set from them?"
Zhuang Rui smiled wryly upon hearing this. The side-scan sonar system that Professor Meng mentioned, also known as "seabed scanning sonar," is an instrument designed and manufactured to detect seabed topography by utilizing the principle of ultrasonic waves propagating and reflecting in water.
Submarine scanning sonar consists of components such as transmitter, transducer, receiver, controller, and recorder.
When a transducer installed on the probe converts the supplied electrical energy into sound energy and emits it as sound waves at a certain frequency toward the seabed, the sound waves propagate rapidly into the seawater at a speed of 1,500 meters per second and scatter in a predetermined direction.
When sound waves reach the seabed, due to the diverse and varied topography of the seabed, some of the sound waves are reflected back in sequence at different speeds and intensities, depending on the shape, properties, and elevation of the reflection point.
The improved seabed scanning sonar can react specifically to gold and silver materials, so this device is not only limited to marine topographical exploration, but can also be used in deep-sea archaeology.
However, Zhuang Rui had the eyes to see, and he never thought he couldn't find the object in the sea, so he never even considered installing an underwater scanning sonar system on his luxurious salvage ship.
Of course, this device is not omnipotent. It only reacts to relatively dense gold and silver materials. If the wreckage of the Awa Maru is severely decomposed, even if it is equipped with underwater scanning sonar, it will be useless.
"The bureau does have some, but it needs to be transported from Beijing, which will take at least two days..."
Director Wu agreed with Zhuang Rui's opinion. In any case, Zhuang Rui would bear all the costs of this salvage operation, so he didn't mind staying a few more days.
Zhuang Rui nodded and said, "Teacher, Director Wu, I think we should use the metal detector to search while waiting for the sonar equipment. We can't just sit around doing nothing, can we?"
Zhuang Rui's words left the maritime bureau divers with deep resentment. Diving to a depth of tens of meters is an extremely physically demanding task, and prolonged diving can also affect lung function and easily lead to occupational diseases.
These guys were naturally unhappy that they had access to high technology but were instead being exploited by the divers. However, Zhuang Rui was the deputy commander-in-chief of the salvage operation, so even if it was just a nominal position, it wasn't something the staff could object to.
"Yes, Xiao Zhuang is right. Let's expand the search area and try to find something as soon as possible..."
When it comes to using official jargon, Director Wu is naturally very skilled. Since he doesn't have to get involved, he immediately nodded in agreement with Zhuang Rui's suggestion.
Professor Meng, returning to the salvage site from over twenty years ago, naturally wanted to find the wreckage of the Awa Maru as soon as possible. He nodded and said, "Thank you all for your hard work. The coordinates from over twenty years ago will definitely have changed. Let's expand the search area to about one hundred meters..."
After the leaders spoke, the divers reluctantly put their diving suits back on. To their surprise, Zhuang Rui also asked for a set of diving equipment and put it on.
Professor Meng noticed Zhuang Rui's actions and asked with some surprise, "Xiao Zhuang, what... what are you doing?"
Diving requires professional training, especially deep-sea diving. The water pressure at a depth of 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 salvaging Song Dynasty shipwrecks and I'm quite familiar with how ships behave on the seabed. Let's go down and take a look together..."
Zhuang Rui made up an excuse on the spot.
"Hey, Xiao Zhuang, diving is something only professionals can do. Don't mess around with this..."
While Zhuang Rui's courage is commendable and his actions worthy of praise, this is no laughing matter, especially given the unpredictable nature of the ocean floor and the constant possibility of danger.
"Teacher, it's alright. When I was searching for Pirate Island, I could dive to a depth of twenty or thirty meters with my bare hands. This area is only forty meters deep, so it's no problem at all..."
Zhuang Rui laughed when he heard this. The current record for free diving seems to be 105 meters. With Zhuang Rui's physique, he dares not say that he can surpass this record, but a depth of only 30 or 40 meters is not a challenge for Zhuang Rui at all.
Moreover, there was a diving suit with decompression function and a series of diving equipment. Zhuang Rui really wanted to go to the seabed to see the scenery. Besides, if he didn't go down, he would probably have to wait at sea for two days in vain.
"Okay, then be careful. If you feel unwell underwater, come back immediately..."
Professor Meng recalled what Zhuang Rui had done at sea and had no doubts about his words. He didn't say much at the moment, since having someone with rich archaeological experience accompany the survey would greatly increase the chances of finding the shipwreck.
Seeing Zhuang Rui, the deputy commander, diving and surveying with them, the divers had no complaints. After Zhuang Rui put on his diving suit, they taught him how to use the propulsion device.
They were using a single-person thruster, which could accelerate the descent. This device was easy to operate, and Zhuang Rui understood it after listening to it once.
"Honey, be careful..."
Qin Xuanbing also heard the news that Zhuang Rui was going to go to sea, and she came over with Fang Fang and Yuan Yuan. The storm that raged for half the night yesterday really scared Qin Xuanbing.
"Hey, it's no big deal, honey. The scenery underwater is beautiful, how about... we go down together?"
Zhuang Rui's nonchalant words immediately caused a stir on the deck. Everyone had thought Zhuang Rui was a man of noble character, but who knew this guy was just going for a seabed tour? And not only did he go alone, but he also wanted to bring his wife along?
"You brat, still joking around now..."
Professor Meng chuckled and scolded Zhuang Rui, and only then did everyone realize that Zhuang Rui was doing this so as not to worry his wife.
Knowing that Zhuang Rui was joking, Qin Xuanbing was no longer very nervous. After giving Zhuang Rui a few more instructions, she watched him go down the spiral staircase.
In terms of scenery, this sea area near the coastline is really not that great. Compared to the pirate island back then, it's worlds apart. In terms of water quality alone, there's simply no comparison between the two.
With the thruster in hand, Zhuang Rui grabbed the handle and started it up. The propeller at the tail of the thruster began to spin, carrying Zhuang Rui down to the seabed.
With an oxygen tank on his back, an oxygen mask on his face, and a walkie-talkie in his ear, Zhuang Rui felt no discomfort except for a slight chill when he descended to a depth of more than 20 meters. This relieved the people on the ship who were watching the monitor.
From the ocean surface to a depth of 200 meters, the area is technically called the upper ocean layer. In this range, sunlight can penetrate the seawater. The water layer from 200 meters to 1000 meters is called the middle ocean layer. Here, sunlight cannot penetrate all the seawater, the light is very weak, and the seawater is a grayish-blue color.
The water layer from 1,000 meters to 4,000 meters is called the semi-deep sea layer. Here, no sunlight can be detected, and it is a pitch-black world. Zhuang Rui and the others only dived to a depth of 40 meters. After reaching the seabed, they could clearly see the surface of the seabed even without turning on the powerful lights. However, out of caution, they turned on the headlights on the thrusters as soon as they reached the seabed.
"Each person is responsible for a 50-meter area. If you feel you're running out of oxygen, immediately ascend..."
After Zhuang Rui and the other four people descended to the seabed, the diving commander monitoring from above gave them orders. The oxygen consumption in the compressed air tanks carried by each person was determined by factors such as water pressure and depth.
Although they were using large bottles, at a depth of 40 meters underwater, they could only last for about an hour at most. Once the oxygen ran out underwater, the consequences would be obvious.
"clear……"
Zhuang Rui was the first to agree, then gestured to the others to indicate the direction he wanted to explore, and then used the thrusters to turn and swim toward his target.
With the help of the thrusters, Zhuang Rui was saved a lot of time. Just a few minutes later, he arrived at a place about 200 meters away from the cruise ship.
Chapter 1018 Finding a Needle in a Haystack (4)
"Huh? How did Deputy Commander Zhuang swim so far out?"
"Yeah, running that far, there probably wouldn't be enough oxygen, right?"
"Xiao Liu, take the speedboat and wait on the sea surface above Deputy Commander Zhuang..."
Zhuang Rui swimming over 200 meters in one go was not a big deal, but the people watching the monitors above couldn't sit still. According to the orders just now, Zhuang Rui could only move within a range of 80 to 100 meters at most, so this was a bit too far.
The ocean is merciless. Generally, when diving in the deep sea, there are salvage ships above to meet you. Otherwise, if you wait for a long time, who knows what kind of accident might happen?
Seeing that Zhuang Rui had rashly swum out of the speedboat's reach, Director Wu quickly used the walkie-talkie to direct the speedboat to the surface where Zhuang Rui had submerged.
Being more than forty meters underwater, Zhuang Rui was naturally unaware of what was happening above. He was currently observing the situation on the seabed, and just as the divers had said, the seabed did indeed look a bit like a garbage dump.
The fishing nets, blackened and mixed with silt, had countless layers covering the seabed. Amidst the nets lay a multitude of household garbage. This environment was completely incomparable to the underwater scenery Zhuang Rui had witnessed on Pirate Island.
Shaking his head slightly, Zhuang Rui took the metal detector off the thruster and turned it on. A ripple invisible to the naked eye spread from the coil of the metal detector to a depth of about three meters on the seabed.
Zhuang Rui knew that the people on the salvage ship could see his actions through the monitors, so he wasn't in a hurry to find the wreckage of the Awa Maru. Instead, he tried to figure out where to avoid it and pretended to search the surrounding area.
"By the way, could we go take a look at that thing that looks like a pearl?"
Knowing full well where the shipwreck was, Zhuang Rui pretended not to know. Time passed slowly on the seabed. After seeing a large sea turtle swimming by on the seabed, Zhuang Rui suddenly remembered that he had sensed that small object.
Thinking of this, Zhuang Rui turned around and swam back to where he came from. At the same time, he released the spiritual energy in his eyes and locked onto that place again. Seven or eight minutes later, Zhuang Rui arrived above a flat seabed.
The tattered fishing nets in this area were completely covered by seabed silt, with some short seaweed growing on them. Fish swam among the seaweed and, instead of avoiding Zhuang Rui, came closer to the light.
"Hmm? Is this... a sea clam?"
Zhuang Rui discovered that the powerful spiritual energy was emanating from below him, but all he could see was a hard, solid mass of mud with cracks on it. It didn't look like a living thing at all.
"Damn, this thing is well hidden..."
Zhuang Rui stretched out his finger and pressed it on the object that looked like mud and no different from the one next to it. The sensation from his fingertip through the diving glove made Zhuang Rui laugh.
The hardness was definitely not something that could be produced by seabed silt. Zhuang Rui was now certain that this was a clam, but it was good at disguising itself, especially the color of its surface, which was almost exactly the same as the color of seabed silt.
"Goodness, this thing is huge! Could it be a clam spirit?"
Zhuang Rui got to work, using both hands to feel along the shell of the clam to both sides. After cleaning away the mud on all four sides, he discovered that the clam was more than a meter long and wide. After cleaning the shell, it actually showed a metallic luster.
"Alright, let's take it up first and then talk about it. We'll ask the restaurant to add extra food tonight..."
Zhuang Rui glanced at his diving watch; there were still more than thirty minutes before they had to surface. He quickly pulled a rope from his pack and wrapped it around the clam's body several times before securing it to the propeller.
"Hey, what's Deputy Commander Zhuang doing? Did he find some shipwreck wreckage?" "Possibly. Look at that dark object; it might be something that broke off from the ship..."
"They really are experts; they made a discovery as soon as they got into the water..."
"It doesn't look like shipwreck to me; it looks more like a clam..."