Magi Craft Meister

691 – Underwater Exploration

On December 19th, Jin and Elsa had barely finished their breakfast before arriving at the dock in Tatsumi Bay.

Finally, they were about to board the submarine and head out for an underwater exploration.

“Jin-nii, what’s the name of this ship?”

Elsa noticed right before they boarded.

“Hmm, you’re right. We need an official name. ‘Submarine’ is too plain, and ‘U-boat’ won’t work either…”

Jin pondered deeply.

“How about… ‘Orca’?”

“I think that’s a good choice.”

“Alright, let’s make sure it looks the part.”

The outer layer of the hull was made from 64 lightweight silver, allowing them to freely change its color. Jin quickly painted it black and white (though technically, it was a matte silver-white).

“Elsa, give it the name.”

“Wait, me!?”

“Bernstein was also named by you, right?”

“…Yeah.”

Still in her regular clothes, Elsa straightened up, faced the new submarine, and proclaimed:

“I hereby name you Orca!”

With a round of applause from Reiko, Edgar, and Jin, the submarine was officially christened.

“Alright, let’s go.”

“Mm.”

Jin took Elsa’s hand, and together they boarded Orca through the side hatch. Reiko and Edgar followed closely behind.

The entrance was double-layered, designed so that once the outer hatch was securely closed, the inner hatch would open.

It worked on the same principle as an airlock on a spaceship.

“Reiko, can I ask you to pilot?”

“Yes, Father. Leave it to me!”

Like an aircraft, the submarine moved in three dimensions—though it didn’t perform maneuvers like spins or loops very often. Without experience, it could be disorienting.

This time, Jin sensibly decided to let Reiko, who was already familiar with the controls from test runs, handle the piloting. She gladly accepted the task.

Once the control core for autopilot gained enough proficiency, Jin planned to try piloting the submarine himself.

“Alright, let’s go.”

The dock gate opened, connecting them to the sea. Using the Aqua Thruster, a propulsion system powered by water magic, the Orca began to move slowly.

“Oh, this is quite comfortable.”

The view, being so close to the surface of the water, was a refreshing change.

Before long, the Orca exited Tatsumi Bay.

“Okay, let’s dive.”

Reiko activated the gravity control magic device, causing the Orca, now slightly heavier than water, to gradually sink beneath the surface.

“We won’t need it while navigating underwater.”

Thanks to the small fins on both sides—acting as main wings—and the fins at the rear—acting as tail wings—the submarine could generate hydrodynamic downforce while moving. This meant they didn’t have to artificially increase the weight any further.

“First, let’s proceed with normal navigation.”

The Orca advanced through the water, powered by the Aqua Thruster, a water magic propulsion system.

“How do we secure free magical ether in the water?”

Elsa asked, voicing a sudden question that came to mind.

“Yes, Elsa. It’s no different from how we do it in the air.”

Reiko replied.

Hearing this, Jin started thinking.

“Hmm, since the particles of free magical ether are so small, they’re probably not affected by whether we’re in the atmosphere or underwater… Which means, there’s a possibility that there’s enough free magical ether even in a vacuum.”

His thoughts were interrupted by Reiko’s voice.

“Switching to Force Field Generator propulsion.”

“O-okay.”

A moment later, a sensation of floating hit them. The Force Field Generator directly influenced the molecules of everything on the ship—including the crew—eliminating any sense of acceleration.

“It’s… fast.”

Outside the window, the blue ocean sped by, with the sea floor clearly visible due to the high water clarity. It was racing past them at an incredible speed.

[We’re traveling at about 300 kilometers per hour], Laojun informed them.

“Any faster than this would be dangerous while Father and the others are aboard.”

Reiko said apologetically.

In reality, the Orca could theoretically reach 3,600 kilometers per hour—Mach 3 in air—because the maximum speed for generating the wind and water barrier was the same for both mediums.

[Considering the worst-case scenario, we do not recommend reaching that speed with humans aboard], Laojun cautioned.

“I get it. So, what’s the maximum diving depth?”

Currently, on Earth, the maximum diving depth for submarines is around 500 to 600 meters. The Russian Sierra-class nuclear submarine is said to reach about 750 meters, though exact data is unclear due to military secrecy.

Some experts even argue that it’s too dangerous to deliberately test a submarine’s limits, as going beyond the pressure resistance can cause it to collapse suddenly.

“I think we can go up to 1,000 meters.”

Reiko said.

“Alright, descend slowly. I’ll use engineering magic to monitor the hull’s distortion. If it gets dangerous, surface immediately using the Force Field Generator.”

Jin instructed.

“Are you sure about this?”

Reiko asked.

“Yeah, I think it’ll be safe with that method.”

Jin wanted to know the maximum diving depth for his undersea exploration.

“Elsa, just in case, please prepare the Warp Gate.”

“Got it.”

Elsa responded.

With that, the Orca began its slow descent.

In reality, the area around Hourai Island marked the end of the continental shelf, a region with a gentle slope about 200 meters deep. Near this area was a trench where the seabed plunged dramatically deeper.

At their current location, Jin estimated the depth to be around 1,500 meters.

Using sonar, they calculated the depth by subtracting the distance to the seabed from the surface measurements.

“Depth… 500… 550… 600 meters.”

They surpassed the diving depth of modern Earth submarines.

“700… 750… 800 meters.”

Outside, it was pitch dark. Jin concentrated, monitoring the hull for any signs of distortion.

“800… 850… 900 meters.”

So far, everything was holding up well. The Gigantopede’s exoskeleton seemed to be performing better than expected.

“950… 1000 meters.”

In reality, a squad of mermaids under Laojun’s command was waiting outside. These mermaids had previously withstood water pressure up to 5000 meters and were quietly observing the Orca.

“1100… 1200 meters.”

The powerful lights illuminated the seabed, which slowly emerged into view. Around the Orca, white floating particles resembling snow—marine snow—drifted in the water. From this point on, the water’s transparency changed sharply, likely due to the ocean currents.

“So beautiful…”

For a moment, the breathtaking scenery made them forget the peril of being in such deep waters.

“1400 meters… we’ve reached the seabed.”

Beneath the Orca lay the ocean floor at a depth of 1400 meters. The hull distortion was still within acceptable limits.

Jin exhaled in relief.

“Let’s try a Grand Search for Underwater Exploration.”

Now that they had reached the seabed, Jin decided to investigate the underwater resources as a precaution.

“Oh?”

“Jin-nii, did you find something?”

Elsa asked.

“Yeah… I found light silver and magical crystals. There are also various metal veins at a relatively shallow depth.”

Laojun, listening to their conversation, chimed in.

“That’s excellent news. I’ll start preparing for the extraction.”

“Good, I’ll leave it to you.”

This unexpected discovery was a pleasant bonus to their exploration.

“Alright, there’s no point in pushing further. Let’s surface.”

Using the Force Generator to ascend, the Orca quickly returned to the surface. Thanks to the airtight barrier specialized in wind attributes within the ship, the risk of decompression or overpressurization was eliminated—an immense advantage.

Magic was entirely unaffected, and the pressure within the vessel remained stable.

Emerging from the pitch-black depths into the bright sea surface brought a sense of relief not only to Elsa but also to Jin.

“That was a huge success. Now, seabed resource exploration will be much easier.”

Jin said, though there was one flaw that became apparent.

That flaw was moisture. The humidity in the cabin had risen due to the water vapor in the exhalations of both Jin and Elsa. In simpler terms, condensation had formed in various places inside the cabin. This issue hadn’t been noticed when Reiko, who didn’t breathe, conducted the tests.

“I guess I’ll have to use the water magic Condense to remove the moisture…”

On the other hand, oxygen recycling worked perfectly. Instead of breaking down all the carbon dioxide in the air, Jin had successfully constructed a Magiformula that monitored the nitrogen-to-oxygen ratio.

In other words, only the amount of oxygen that had been consumed was regenerated, making the system more efficient. The separated carbon was compacted into graphite.

“Maybe I should make some pencils…”

Jin mused.

But, back to the story.

After surfacing and refreshing the air, Jin set off once more, this time to enjoy the underwater scenery at a more leisurely speed of about 50 kilometers per hour.

“Ah, this pace feels just right.”

Jin remarked.

They could see colorful fish swimming around.

Jin and Elsa spent some time enjoying the underwater scenery after that.

Of course, it goes without saying that they took measures to address the humidity once they returned.