Ace was the key figure in this ascent.
It was precisely because of him that Leo and the others had not arranged any fuel—otherwise, with current fuel technology, finding reliable fuel would have been a major problem in itself.
Modern hot air balloons used methane or liquefied gas; before that, they used kerosene.
It was already quite good that Leo and the others could find kerosene, but in Leo's judgment, kerosene in the One Piece World could not lift a hot air balloon—the energy efficiency was too low. A hot air balloon already had limited payload capacity, and carrying a large amount of kerosene would make it even harder to carry more people.
Ace only weighed around 120 jin now, and when he transformed into an element, his weight could reach zero. This meant that not only could he provide ample firepower, but he could even make room for another person in the basket.
The three experimental hot air balloons had all been set up in the open space.
All three baskets were woven from rattan and were very large. Two people as tall as William, who stood five meters tall, could sit inside one, while six or seven normally sized people could fit in each.
Thick cables were tied to the four corners of the baskets. These cables had originally been used to secure ships; thick and long, they were meant to withstand wind and waves. Now, were they going to withstand air currents instead?
In fact, apart from ocean currents, most wind and waves were caused by air currents. A hot air balloon could only travel by relying on those currents, so a navigator was crucial.
In fact, even someone like Golden Lion Shiki, a Float-Float Fruit user capable of making islands fly freely through the sky, would