132. Seven all forty three
6 months later.
May 2, 2003.
In the middle of the West Sea.
As I lifted my head to stretch for a moment, a black face looked down at me.
“Ugh-! It’s a surprise!”
It was In-cheol’s face that had been tanned in the intense sunlight for a week.
I let out a long sigh and continued.
“men and horses! Put some sunscreen on your face! A real surprise… .”
“haha-! Are you surprised? sorry. But I heard that Ji-eun has a more tanned face like this?”
I smiled mischievously, and In-cheol continued speaking with a serious expression.
“It’s been a week today… Could it be that I can’t find this forever?”
I said, turning my head toward the monitor showing the echo echo signal in real time from the echo sounder.
“but… If it’s not here, maybe the sunken location is wrong, or the ship is buried under the muddy puddle… … .”
I said, checking the echo recordings received by the echo sounder again.
“Incheol-ah… ! It’s here.”
“what? really? Really?”
I said, checking the recorded echocardiogram again.
“Yeah, really. Turn off the boat and check the GPS coordinates.”
When the ship’s noisy engine stops, only then can you hear the sound of waves crashing against the ship and the sound of seagulls chirping in the distance.
After staring at the echo sounder monitor for over three hours in the morning, it felt like my eyes would fall out.
“Aww—!”
I stretched out loudly and got up from my seat, and In-cheol took my seat and checked the recorder on the echo sounder and said:
“To me, they all look like the same sonic signal… What do you see that there is a sunken ship down here?”
An echo sounder is a device that measures water depth using sound waves. The principle is the same as that of a sonar, usually called SONAR.
When a sound wave is shot from here, the sound wave spreads out to the bottom of the water surface, and the sound wave hitting the floor is reflected and returned to this place.
For reference, the speed of sound waves in water is 1480 m/s. In other words, if the depth of the water is 74 meters, the total travel distance of 74 meters and the return distance of 74 meters is 148 meters. The measuring device is an echo sounder.
In-cheol nodded at my explanation and said.
“then… You mean a sunken ship jutting high above the sea floor?”
“There is, too, but I didn’t actually figure it out. The change in depth is not that detailed.”
“okay? So how did you find out?”
“I’ll tell you about that in a little while. Let’s do this first.”
I started preparing an underwater drone to send down under the sea. It’s actually an underwater drone… It’s still crude and can only move back and forth and rotate with a waterproof camera attached.
read at noblemtl.com
Note that underwater drones cannot move up and down. In other words, you have to connect the cable from the ship and send it down, and you need to adjust the depth of the drone by lowering and pulling the cable from the top of the ship.
Still, with this kind of function, it will be possible to check the sunken ship, which is today’s goal, on the camera screen.
I attached the waterproof camera and lighting that Incheol brought to the underwater drone, and finished the work of connecting wires and cables. After a while we tossed the underwater drone into the sea and began to unravel the cables little by little.
“Are you sure the Japanese cargo ship is down here?”
I nodded my head at In-cheol’s question, and In-cheol said with a frustrated expression.
“But won’t you tell me how you found out?”
“ah… ! it?”
I continued as I slowly lowered the cable.
“You know how much sound waves reflect off the floor.”
“How much sound waves are reflected?”
“Yeah, the floor here is all muddy. If the bottom had not been muddy, it would have been difficult to know that there was a sunken ship.”
“I found out because it was a muddy field… What does that mean?”
“When sound waves are reflected, if the material is a hard material like rock, the sound waves are reflected well… Conversely, if it is a soft material like mud, the intensity of the reflected sound wave will be drastically reduced.”
Incheol nodded, and I continued.
“But when I passed this place a while ago, the intensity of the echoed sound wave I received jumped. It means there’s something solid down here.”
Incheol tilted his head and said.
“It could be a reef.”
Incheol is right. Most of the bottom of the West Sea is covered with pearls, but reefs are dotted here and there.
I nodded and said.
“I’m right, this is definitely the stomach.”
“How are you so sure this is a sunken ship?”
“The expected shape is that of a ship.”
At my words, Incheol said while checking the echo sounder monitor.
“What do you expect? Does anything like that come from here?”
I smiled and shook my head.
A little while ago we were driving the boat at a constant speed and activated the echo sounder. And because of the relatively shallow water depth of 79 meters on average,
The sonic signal returned by hitting a hard part of the sea floor was received fairly cleanly.
In the not-too-distant future, imaging technology that combines incoming sound waves to create three-dimensional images will be developed. And perhaps the most used 3D imaging technology is in obstetrics and gynecology hospitals. A three-dimensional ultrasound image of a pregnant fetus.
However, this 3D imaging technology is not made with such a complex algorithm. A two-dimensional cross-sectional image is created using the sound wave information received every hour, and a three-dimensional image is constructed by connecting the cross-sectional images created in this way in chronological order.
For example, if the sunken Shigemitsu lies long parallel to the direction of our ship, we will receive a sound wave signal reflected from the Shigemitsu for a relatively long time.
Conversely, if the Shigemitsu is located perpendicular to the direction of our ship, we will receive a stronger echo sound wave for a short period of time.
Of course, in order to create a high-resolution three-dimensional image, it is necessary to analyze and calculate the received radio signal in units of almost one thousandth of a second.
When I finished my explanation, Incheol nodded and said.
“Hmm-! From what I’ve heard, the 3D imaging algorithm… Do you think I can make it myself?”
“You said It’s not that complicated.”
At my words, Incheol opened her eyes thinly and said.
“By the way… Jung-ho, you mean you ran that algorithm in your head a while ago.”
I smiled bitterly, and Incheol narrowed his forehead and opened his mouth.
“You monster. therefore… How did the Shigemitsu sink below this?”
I said looking around.
“Is this south? So, the sunken ship looks like it stretches from north to south, and because the east-facing side has a lot of curves, it looks like the ship’s deck is lying on the east side.”
Incheol nodded at my words, and I said while checking the remaining length of the cable connected to the underwater drone.
“I think it’s almost all gone… How deep is the drone now?”
Incheol said while checking the signal coming from the drone’s pressure sensor.
“73 meters… … . Almost 74 meters now.”
I fixed the cable and said to Incheol.
“OK! Now, shall we take a look at what the Shigemitsu looks like?”
At my words, Incheol rubbed his hands together with a look of anticipation and said.
“Five-! I’m a little nervous about this… !”
Will you be as nervous as me?
It took almost two years to design the underwater drone, and after being discharged last October, I have been immersed in making the underwater drone until now.
After a total of 11 failures, the current version 12 came out a month ago, and as soon as I completed the counterweight device that balances the drone when there is a flow of water like a bird for the past month, I ran to Mokpo Port along the way with Incheol. it was
With trembling hands, I turned on the lights and then the camera.
“… !”
“yes? what’s this?”
The screen of the laptop was full of hazy fog.
Incheol continued.
“Perhaps… Could it be that moisture got inside the waterproof cover of the camera?”
When you go down to 74 meters in depth, the temperature of the sea water drops sharply, so moisture on the inside of the waterproof cover of the camera condenses and the screen may look hazy.
I shook my head at Incheol’s question.
“No, it’s not because of the humidity because I put a dehumidifier along with the camera.”
“but… When I tested the camera in Yangyang last winter, nothing like this happened.”
I focused on the computer monitor screen, and after watching the video the camera was sending for a while, I didn’t know what the problem was.
I opened my mouth with a serious expression.
“It’s like a float coming up from the bottom of the sea.”
“What is coming up from the floor?”
“Damn.”
Mud grains that make up mud are very small particles on the order of micrometers. So even with the slightest movement of water, the mud particles float and the seawater becomes colloidal.
“Is it because of the waves?”
I shook my head at Incheol’s question and said.
“That’s not right. The waves aren’t that bad right now, and no matter how big the waves on the water, they can’t affect you down to a depth of 70 meters.”
“Then for what?”
“Perhaps… Could it be because of the birds? Do you remember what the birds are like here?”
“If you go a little further south, there are a lot of tides, but here the tides aren’t that strong.”
Incheol continued, checking the calendar and clock on the ship’s cab.
“And now is the time to change from ebb to ebb.”
This means that now is a time of little tide. In other words, the reason the mud particles floated is not because of the movement of water, but because the particles are too small and light.
Incheol and I let out a long sigh almost at the same time, and started pulling up the cable connected to the underwater drone.
There was silence until the underwater drone was lifted out of the water.
While I was disconnecting the cable from the drone I took out, Incheol said to me.
“Jeong-ho, do you have any plans in mind? Is not it? Please tell me so, huh?”
So far, we have been faced with countless problems, and in the end we have solved all of them and have come this far. But now with the Shigemitsu in front of us, we are faced with a new problem.
By the way… This problem is different from the problems we have encountered so far.
Mechanical problems that occurred during the underwater drone’s manufacturing process, waterproof problems with cameras and lighting, the problem of transferring image information directly from a digital camera to a computer without going through a memory card, a problem with weakening of electrical signals in cables longer than 80 meters, etc. All the problems so far have been the sort of thing that you can reach out to.
But now… It’s a problem at depths of 70 meters.
I can’t even reach it… It is a natural phenomenon beyond human control.
At Incheol’s words, I shook my head and said.
“Well. To be honest, I don’t know what to do with this either.”
In response to my answer, In-cheol, who wrapped his head with both hands, collapsed on the floor, and I also sat on the floor and looked at In-cheol.
When our eyes met like that, In-cheol showed a disappointing smile and said.
“it’s tough! tiring! This is really endless. OMG–!”
As Incheol said, there is really no end.
When we crossed one mountain, there was another mountain, and when we crossed that mountain, a higher mountain was waiting for us.
4 billion won.
Also… This isn’t that much money.
I lay flat on the deck as if I had collapsed.
blue sky… . And a single white cloud floating in the sky.
Whenever the ship shakes in the waves, the fragment clouds in the sky also shake. It’s like dancing.
Come to think of it, a lot has happened in the past six months.
After I was discharged from the military, I set up an officetel and became independent, and with the $1 million I received from Director Jackson, I purchased a small three-story commercial building near Mok-dong.
The building was owned by Yoon Sung Soft, not my name, but the ownership stake in the company changed in the process. Including Yoon Seok hyung 50%, Incheol 5%, and Myungsu hyung 5%, I got 45% of the shares.
The ground floor of the purchased shopping mall is currently used as an office and server room for 17 executives and employees of Yunseong Soft, and the basement is used as a workroom by me.
In the meantime, while I was working on making an underwater drone in an underground workshop there… Incheol joined a club called ＜I Like the Sea>.
It was a boat fishing club, and In-cheol received a lot of joy from the men in their 40s and 50s, and received all the know-how and techniques for fishing.
For example, contact details of ship owners who rent small ships at Mokpo Port, how to skillfully operate small ships under 5 tons, and how to cook freshly caught fish sashimi and make delicious maeuntang… such know-how.
Incheol got up from his seat and took out his fishing rod and said.
“It seems that fishing for gold ingots today is ruined, but let’s go catch one of our red snapper. I’ll make the hot spicy soup cold.”