After spending an entire day tinkering this way and that, the artificial island had turned out quite nicely.
The following morning, on February 2nd:
"We really need to settle on a name soon," Jin spoke up.
"The management magi-brain is finished too, so I want to get everything fully operational. To do that, we need to name them."
Incidentally, the management magi-brain Mentor, who piloted Deus Ex Machina, would remain as it was.
Jin was leaning toward naming the brain Poseidon. Following that train of thought, he wanted to give the island a name connected to Greek mythology as well.
If I go with that theme, maybe Atlantis...? But wasn't that supposed to be a continent...?
"You should definitely be the one to name it, Jin."
"Kufu, I agree."
Reinhard spoke on behalf of the group, and Saki chimed in with her agreement.
At this point, he rather regretted having already used Avalon and Onogoro Island elsewhere.
"What else is there...? Anything good...?"
Jin racked his brain, pondering various utopias.
"Shambhala... El Dorado... Neither really feels right... Ah, come to think of it, wasn't there one in Greece?"
A Greek utopia suddenly came to mind.
"Arcadia."
Arcadia was an ancient region in Greece that was later remembered as a pastoral paradise, eventually becoming synonymous with utopia itself.
In English, it was sometimes rendered as Arcadia, Arkadia, or similar variations.
"Arcadia, huh? That has a nice ring to it."
"I think it sounds lovely."
"Yeah, it's great."
Surprisingly, it was an immediate hit with everyone.
There was no point in overthinking it further.
"Alright, the island's name will be Arcadia. And the management magi-brain will be Poseidon," Jin declared.
When he explained the origin of the names as best as he could remember:
"Oho, not bad at all."
"A utopia and the sea god. They fit together perfectly."
The reactions were overwhelmingly positive.
"Management magi-brain, Wake up. Your name is Poseidon."
"Yes. I am Poseidon."
"Manage and oversee this artificial island, Arcadia."
"Understood, Jin-sama."
Since the nominal owner was Deus Ex Machina, it was instructed not to address Jin as "My Lord."
And with that, Deus Ex Machina's base, Arcadia, was officially born.
"...Good grief, it's nothing but construction, construction, construction this year..."
"You say that, but you look like you're having a blast, aren't you?"
Currently, Jin and the others were in the middle of building the naval vessels to be stationed at Arcadia.
Reiko assisted at Jin's side, while the Smiths carried materials and assembled components according to his instructions.
"Hmm, I'd like this part done this way."
And one more person, Marcia, was actively offering her input.
There was a good reason for this.
As Jin put it, "If I design everything myself, they all end up looking the same."
Hourai Island already had an eight-seater submersible called Shachi. Since it would be undesirable for the new vessels to look identical to it, he was taking full advantage of Marcia's advice.
The only real downside was that construction proceeded at a slower pace, which posed no actual problem.
"I see. So when Marcia designs one, this is what a submersible looks like."
"Pretty much....Since you mentioned it would operate on the surface as well, I added a deck."
Because of that, rather than a sleek cigar-shaped hull, it featured a deck reminiscent of a World War II vessel. Frankly speaking, it looked a lot like an I-class submarine.
To Jin, it brought to mind the submarines featured in a manga he had read long ago.
It measured 20 meters in total length, with a maximum underwater speed of 100 km/h and a surface speed of 80 km/h. It was propelled by a Magi Jet Engine, with a maximum diving depth of 100 meters.
"Well, with a water-repelling barrier it could easily dive to 1,000 meters, and with a force generator it could even exceed the speed of sound underwater."
"Let's see... you mean over 1,500 meters per second? That's incredible."
"Though I doubt there'll ever be a need for that," Jin added offhandedly.
"The crew will be the Marine squad, so we don't have to worry about oxygen either."
Even so, since they could not entirely rule out the possibility of carrying human passengers, a reasonable degree of habitability had been incorporated into the interior.
"There might be occasions where we have to conduct rescues, after all."
"That's true....What about armaments?"
"Torpedoes and depth charges using mana bombs. Plus a Magi Trans Cannon."
With a defensive barrier installed as well, Jin noted that it should be able to handle almost any situation.
"What are you going to name it?"
"Let's see..."
After pondering for a moment, Jin decided.
"Let's call it the Coelacanth."
His reasoning was simply that it slightly resembled that submarine from the manga he had read back in the day.
"We'll need ten of these, I suppose."
He decided to leave the mass production to the Smiths.
"Next up are the small high-speed boats."
In terms of Hourai Island's lineup, these would fill the role of the Hydro and Stream series.
"I'd definitely recommend a trimaran," Marcia suggested.
"I figured you'd say that."
"Though if we do that, won't it end up looking just like a Stream?" Jin asked.
"Ah, in that case, I have another design in mind."
Marcia grabbed a notepad from the workshop desk, sketched out a hull, and showed it to him.
It featured a large central hull flanked by considerably smaller outriggers on either side.
"Oh, this works too."
"My father and I have built and tested countless hulls over the years. That's one thing I can brag about, even to you, Jin."
"You're right. This is a huge help."
Even though both were trimarans, the design gave off a completely different impression.
"Alright, approved."
With the design settled, Jin, Reiko, Marcia, and the Smiths set to work crafting the small high-speed boats.
"Normally, it should seat five, with enough room to carry up to ten during rescue operations."
"In that case, an overall length of about six to seven meters should do the trick."
As expected of a master shipwright, Marcia could gauge the necessary vessel size just from the passenger capacity alone.
"Then let's go with that. For the framework, we'll use 64 light silver..."
And so, Jin continued building at a leisurely pace, happily matching Marcia's rhythm.