"What is it?　What is this?"

Marcia turns her head to look at the parts that bear no resemblance to the oar. Jin said,

"Just watch and see. Reiko, help me put it together."

"Yes, sir."

Reiko carries the heavy parts and Jin attaches them to the catamaran. Soon it was completed.

"Okay, it's done. Let's float it and see how it balances, and then let's run it.

It was attached to the rear of the center hull of the catamaran.

There is a waterwheel at the very back and a round wheel next to the waterwheel. The wheel had a V-shaped groove on it, and a belt made of a flexible material hung from it.

The belt hung between the other wheel and the wheel.

On the other wheel, there was an L-shaped curved bar sticking out from both sides, a seat a little behind it, and a handle a little in front of it.

As you may have already guessed, Jin made a propulsion device of the type that can be pedaled like a bicycle to turn a water wheel. You often see such a device at tourist attractions such as ponds and lakes.

But when Marcia saw it for the first time, she asked him, "How can you go forward like this?

"Are you sure you can go forward like this?

She looked worried.

"Well, let's give it a try," she said.

So, with the help of Arrow the golem, she floats the boat on the sea. And then..,

"Well then, I'll steer the boat, Reiko, press the pedal."

"What?　Are you all right?"

Marcia still looks worried, but Jin smiles,

"Yeah. I'll take care of it."

"I'm ready, my ...... brother."

"Okay, let's go. We'll take it slow at first.

Yes, sir.

Reiko presses the pedal. Then the waterwheel starts to turn, and the water is scraped backward. The reaction pulls the boat forward.

"Oh!　It's moving!"

And then the boat moves out of the bathing area and gradually picks up speed.

"Yeah, that's not so bad."

"Father, would you like to go a little faster?"

"No, this is about right. Reiko, what is the current output of the ether converter?

Yes, about 5 percent.

I see... It's not as efficient as I thought. I'll try to change the shape of the water wheel.

Jin then uses forming while sitting in the pilot's seat. If there is physical contact, the water wheel can be used at a distance of about 3 meters. The efficiency is inversely proportional to the distance, though.

"Oh, it looks a little better this time.

After a few tweaks, the speed is improved by more than 30% compared to the first time.

"Okay, let's go back."

Jin makes a U-turn and returns to the dock. He was greeted by a jubilant Marcia.

"Jin!　You're amazing!　You're a genius!"

Jin is embarrassed and Reiko is proud at the unreserved praise.

"Just one more thing to add and we'll be all set.

"Is there something more you need?"

Marcia asked back at Jin's tone.

"Yeah. I want to add a cover to prevent the spray from the waterwheel.

As the waterwheel spun at high speed, the centrifugal force sent spray flying in all directions, wetting the backs of both Reiko and Jin.

"Do this like this. Forming. Okay, it's done."

"Well, can I try to ride it?"

Seeing Marcia itching to ride, Jin smiled wryly,

"Yes. But first, Marcia, as the owner of this boat, you should give it a name, too."

"Hmm?　Oh, I see. How about ......<>?"

"That's a good idea.　How about ......<> to match the name?

"Oh?　Ahhh?"

The catamaran's hull changed from the wooden color it had been until now to a white color, befitting the name Cygnus.

"What did you do?

"I simply removed the pigment and made it white."

In short, bleaching. In fact, they are waterproofed. And then he says..,

"Arrow, come here. Okay, plating."

The nickel from the impurities separated from the bronze is plated on the surface of the arrow. Now the arrow has a silver-gray color and is resistant to corrosion.

"Wow, that's great!　Gin, are you sure you're ready for this?　Are you sure?"

Marcia looked at him as if she wanted to get on board as soon as possible,

"Yeah. "Yeah. Take care of yourself."

"Okay!　I'm off!　Arrow, please!

Hey, excuse me.

Cygnus, launch!

Since Marcia has the highest command authority, the cooperation between Arrow and Marcia is smooth from the start. Marcia starts to fly.

Splashing water from the stern, she glides along the water. Jin looked over at her and said,

"Ah, water turbines are not so efficient after all..." he said to himself.

he said to himself. Reiko overheard him.

"Father, are you still dissatisfied with that?"

Reiko had knowledge passed down from the previous Magecraft Meister, Adriana Barbora Zetsi, but there was no propulsion engine like the one Jin had created this time.

"Ah. It's more efficient because it's not a back-and-forth motion like an oar, but it's still a lot of splashing ......."

Yes, the splashes and waves mean the loss of energy. Jin, with his knowledge of the modern earth, wanted to use screw propulsion.

"But, there are many problems in turning a screw..." he said.

First of all, the direction of rotation changes 90 degrees from the pedal. And the rotation speed is not enough. Screws are inefficient unless they rotate at high rpm.

"I can't make bevel gears (bevel gears) yet. ......"

So far, Jin has not been able to make gears. Gears require precision because two or more pieces mesh with each other.

He could make bearing balls by simply controlling the weight parameter, but gears, with their modules, pitches, and involute curves, are a bit out of his league at the moment.

"I guess that means I have to build a machine tool, right?"

I worked in such a factory, so I have used lathes and milling machines, and I know the approximate structure, but so far I have not been able to reproduce it due to lack of time.

"Well, that's something we'll have to work on in the laboratory.

After a while, returned with a kick of water.

"Welcome home.

When Jin greeted her at the pier, Marcia looked excited,

"Jin!　This ship is amazing!　I've never seen such a fast boat!

"That's great. So, do you have any complaints or concerns?

Jin asked,

"Yes, I have no complaints about the propulsion. "Yes, I have no complaints about the propulsion. It would be nice if it were a little more maneuverable.

Catamarans have long, narrow hulls, which makes them difficult to maneuver, even though they have good straightness.

"Hmmm, but don't you need to be able to turn in small circles to compete?

"Well, yes. Basically, we just leave the harbor, go around the island at the turnaround point, and come back to the goal.

But," Marcia adds.

"There's nothing wrong with trying to get a better hull, is there?"

Marcia laughs at that,

"That's right. Once we are satisfied, progress stops.

Jin agreed.

It was almost dusk and the wind had calmed down. Jin and the others called it a day.