Jin’s vessel, the Dolphin, was set to run the course designated for the race.
This course had been laid out by Jin and Marikka just the night before and was making its debut today. No one had ever run it, making this a blind trial for everyone involved.
By having the Dolphin navigate the route, it would serve as a crucial reference for the participants. Since their time would also be recorded, it was effectively a demonstration run—one that would set the standard and provide a target time for the official competitors.
The spectators watched the screens with bated breath.
"Now, the demonstration run begins!"
At the announcement, the Dolphin surged from the starting line with a fierce burst of speed.
A collective "Ohhh!" rose from the crowd.
Leaving a brilliant white wake in its trail, the Dolphin dashed down the first straightaway. This initial stretch was approximately five kilometers long, a section clearly designed to test the boat’s raw power.
"Estimated speed: ninety kilometers per hour! That is incredible!"
In Japan, the speed of competitive boat racing is said to be around eighty to ninety kilometers per hour, so the Dolphin was already matching that pace.
However, the vessel was not yet at full throttle.
"Oh! The—the speed is still climbing! It’s over a hundred kilometers per hour! Estimated speed: one hundred twenty kilometers per hour!"
The initial stir among the crowd transformed into thunderous cheers.
While small racing boats are generally considered dangerous at a hundred kilometers per hour, the Dolphin had a total length of nine meters. Furthermore, as a trimaran, its stability was significantly higher.
"Well, this is what we call 'hydroplaning,' a phenomenon where a vessel lifts up when traveling at high speeds over water. With a monohull, the boat lifts while leaving only the stern in contact with the water; however, this is unstable because the hull is supported by only a single point. That is where the trimaran design excels."
Hydroplaning was a feat the waterwheel-driven Cygnus had been unable to achieve.
Incidentally, the phenomenon where an automobile’s tires lift because the treads cannot fully drain water when driving at high speeds on a wet road is also called hydroplaning.
The Dolphin maintained three points of contact with the sea surface as it dashed along at ultra-high speeds.
An airship floating in the sky filmed the entire run. This airship was Marikka’s creation, boasting a maximum speed of one hundred sixty kilometers per hour, allowing it to keep pace with the Dolphin effortlessly.
In less than three minutes, the first corner arrived—a sharp right-angle turn immediately following the straight. With a corner radius of only twenty meters, it was incredibly tight.
Since it was impossible to turn while maintaining maximum velocity, the Dolphin decelerated as it approached the bend.
"Decelerating before the first corner! However, it still looks to be going over fifty kilometers per hour!"
To compare with boat racing again, professional racers there typically execute turns while maintaining nearly maximum speed.
＊ ＊ ＊
"She slowed down quite a lot," Jin muttered while watching the screen.
"Father, I believe the sensation of that speed is quite frightening for a human who isn't accustomed to it," Reiko interjected with a rare word of dissent.
"I suppose you're right. Especially since Edith is only a fifteen-year-old girl."
No matter how active or spirited she might be, scary things were still scary, Jin conceded.
"Besides, I did set the boat’s handling to be Mild."
"That is true."
＊ ＊ ＊
The Dolphin opened its side thrusters to full power.
The lifted hull tilted diagonally relative to its direction of travel. Naturally, the force of the propulsion system also shifted diagonally, generating a "centripetal force" directed toward the inside of the turn.
According to the laws of mechanics, the Dolphin changed its course in a direction synthesized from the force of inertia and this centripetal force.
"The Dolphin is changing direction without even using a rudder! Such methods have been explored before, but to see it operated so masterfully—as expected of the Magi Craft Meister!"
A great cheer erupted from the audience.
After the right-angle curve came a high-speed section that traced a large arc. The radius of that arc shifted subtly throughout the bend; one could easily imagine that a pilot preoccupied with raw speed would end up veering off course.
"The Dolphin is dashing at maximum speed! It’s now entering the second corner, the 500R!"
While this section could be taken at top speed, it would be difficult if the vessel's stability was poor. Circular motion at one hundred twenty kilometers per hour generates significant centrifugal force, which threatens to upend a boat's posture.
Since centrifugal force acts on the center of gravity, if that center is above the water's surface, the boat will tilt outward. Because a boat navigating at high speed is lifted, its center of gravity is almost certainly above the waterline.
Taking that into account, Jin had determined the mounting positions and injection angles of the side thrusters through several rounds of trial and error. Of course, since the test pilot had been Reiko, those experiments had been conducted at maximum speed without the slightest hesitation.
"The Dolphin clears the 500R, drawing a beautiful arc!"
Once past that curve, the course returned to a straight heading back toward the island. Waiting just before the shore was a hairpin turn with a thirty-meter radius.
"Oooooh!"
The crowd roared. Though she had dropped her speed slightly, Edith had nailed the turn at a pace far faster than she had at the first corner.
"She’s getting used to it a little, I see," Jin murmured softly.
After the course took another straight, it entered the technical area—a series of continuous zigzag curves with ten-meter radii.
The direction changed dizzyingly from right to left. An inexperienced pilot would surely suffer from motion sickness; however, while that might have been a concern for Edith, the actual race would be fought by golems, so that worry didn't apply to the contestants.
After passing through an area combining short straights and right-angle curves, the course became a final straight heading toward the island once more. After executing a 180-degree turn near the shore, the finish line followed immediately.
One lap was approximately thirty-six kilometers. At an average speed of a hundred kilometers per hour, the run would take a little under twenty-two minutes.
"The Dolphin has returned! The time is... twenty-one minutes, thirty-six seconds! That’s a record average speed of one hundred kilometers per hour!!"
"That’s... not bad, I guess," Jin said, looking satisfied.
The previous night, when Reiko had tested the boat after the course was finalized, she had clocked in at exactly nineteen minutes flat using the same settings. That was an average speed of about one hundred thirteen kilometers per hour. For a human like Edith, this was a more than respectable time.
In the actual race, the participants were scheduled to run two laps of this course.
＊ ＊ ＊
"Now, it seems all ships have completed their preparations!"
"I’m looking forward to this."
As the announcements played, the ten vessels began to line up at the starting position.
"Good luck, everyone," Jin whispered. He couldn't play favorites, though he found himself feeling a bit concerned for the youngest participant, Rubina.
"Vessels one through ten are lined up in a single row!"
A red rope was lowered from the airship in front of the ten boats. It would be retracted the moment the race started.
"Jin-sama, how do you expect this race to unfold?" Trihart, sitting beside him, asked.
"Let's see... It seems everyone has put a lot of ingenuity into their vessels, so I can't predict anything for certain. However, I'm particularly interested in Numbers 7 and 10."
Jin explained that he wanted to see how well they had brought their new experimental concepts up to a practical level.
"I see. That makes sense."
"5... 4... 3... 2... 1..."
Finally, the race began.