In the wake of the heated competition, the now-cleared course was filled with the sight of boats zipping around as their pilots pleased.
"Looking at them now, they’ve all truly improved."
Magi-craft had regressed following the Great Magic War seven hundred and fifty years ago—though some records still claimed it was only three hundred and fifty. Four hundred years ago, technology still hadn't returned to its former heights, but now...
"It’s safe to say that, at least here on Onogoro Island, they’ve returned to that level. If there’s one thing they’re still missing..."
"Father, what would that be?" Reiko asked.
"Scientific knowledge, I suppose."
Jin mused that four hundred years ago, the foundation for such things hadn't been laid. Generally speaking, knowledge levels had hovered around those of an elementary school student; even in Avalon, they had only reached a middle school level at best.
The current Jin speculated that after the original Jin passed away, the balance of that knowledge hadn't been managed quite right.
"Hey, hey, Ances—Jin-sama! Let me ride in your boat!"
"Eh?"
While Jin was lost in thought, Rubina had come over to pester him.
"Well, I don't mind," he said with a smile.
"Yay!"
Jin looked at Rubina warmly. To him, she felt like a perfect blend of Hanna and Beena. Even Reiko seemed to find the girl charming in her own way; she didn't hold a grudge about Rubina's earlier outbursts or the fact that she had called Reiko a fake. Jin himself held high expectations for this promising descendant.
Jin, Reiko, and Rubina headed toward the pier where the Dolphin was moored. There, they were met by Natalia. She was a slender woman with blonde hair and blue eyes who bore a striking resemblance to Marcia.
"Oh, Jin-sama and Rubina. Are you perhaps heading out on Jin-sama's boat?"
Since they were walking right toward it, the answer was obvious.
"Um, if you wouldn't mind... could I join you as well?"
"Sure, why not? It seats five."
"Wow, thank you so much!"
"Alright, put these on first."
Jin handed out the simple life jackets kept aboard the Dolphin. Since it was a five-seater, it carried five sets.
"I’ll be fine," Rubina insisted. "I’m a great swimmer."
"No," Jin replied firmly. "You never know what might happen. It's important to reduce risk however much you can."
"...Okaay."
Jin and Natalia donned their life jackets and boarded the Dolphin; only Reiko remained without one. After untying the mooring lines, Reiko hopped lightly onto the boat.
"Jin-sama, would you mind letting me pilot?" Natalia asked.
Jin gave his consent. "Sure. Let's see... this is the rudder, and this is the throttle."
"Yes, I understand. It's the same as my boat."
He gave a brief explanation, but since the control scheme was standardized, she seemed comfortable.
"Well then, shall we?"
"Yes, here we go."
Natalia slowly set the Dolphin in motion.
"Oh, it's so easy to handle!"
"Huh? What do you mean?" Rubina asked, leaning in.
As she steered the Dolphin toward the open sea, Natalia searched for the words. "Hmm, how should I put it? The response from the throttle and the rudder... it’s neither too sensitive nor too sluggish."
"That’s likely because this boat isn’t set up specifically for racing," Jin interjected.
He explained that for a race-spec vessel, the rudder and throttle would be tuned for much more aggressive responses.
"In a race, the settings assume a golem is piloting, not a human."
"Ah, so this boat is still set up for when Edith piloted it?"
"Exactly."
Jin added that if Reiko were the one at the helm, he would reduce the 'play' in the controls to a micro-class level.
"But if a human tried to pilot it like that, it would be impossibly difficult to handle, wouldn't it?"
"That’s true."
"Precisely. That’s why I usually leave it de-tuned."
Rubina's eyes widened. "Wait? Does that mean you weren't at full power during the demonstration run?"
Jin nodded. "Yeah. After all, Edith was the one piloting."
"I-I see... By the way, just how fast is it at full power?"
"Let's see... probably about one and a half times what you saw."
"..."
"..."
After spending the last few days with him, Rubina understood that Jin didn't joke about such things. Furthermore, she suspected his estimates were conservative—it was likely closer to double. Natalia felt the same. Both women were beginning to grasp, deep in their hearts, what the title of Magi Craft Meister truly signified.
"There’s something called a 'safety factor.' It depends on how and where a machine is used, so I can't give you a single number for every situation, but I tend to keep mine high. I’m a bit of a coward, you see."
Only Reiko realized that Jin's self-described 'cowardice' was the very thing that drove him to create machines with such outrageous performance levels. Natalia and Rubina, however, listened to his explanation with dead-serious expressions.
"Along with giving the rudder some play, I gave the hull straight-line stability. In other words, if you let go of the steering, the rudder returns to the central position and the boat naturally travels straight."
"I see. That’s very educational." Natalia nodded, looking pleased.
"From what I've seen, what you all lack most is experience. It's not enough to just build things; you need to understand the environments where they'll actually be used."
While they talked, the Dolphin had moved quite far offshore.
"Alright, I'm going to pick up the pace."
With a quick warning, Natalia opened the throttle. The Dolphin accelerated sharply.
"...It’s so stable."
"High-speed stability is a critical performance metric," Jin explained calmly. "This design comes from the experience of building several boats—and building them without cutting corners or compromising."
When it came to tramarans on Hourai Island, the Stream series reigned supreme. Jin had constantly refined and upgraded them based on data gathered during their operation. The Dolphin was the culmination of all that accumulated knowledge.
"I see. This is incredibly helpful," Natalia said, her voice bright as she steered.
"In that case, what do you do when you're making something for the very first time, Jin-sama?" Rubina asked.
"Let's see. It depends on the scale, but if it's something large, I start with a model. One-tenth or one-fifth scale, for example."
"Ah, that makes sense."
"You accumulate data that way before building a prototype. It might seem like a roundabout way, but it's reliable, and you end up finishing the project faster in the long run."
"I wonder... if that's really true?" Rubina mused.
"Is that a bit too difficult for the young Rubina to grasp?" Jin teased.
Impulsive, headstrong, and impatient—those were the words that best described Rubina. She was still too young to have mastered the art of caution. Jin realized he would have to take his time teaching her.