It was the next morning.
The first pale light had barely appeared on the horizon when the Going Merry set sail for the waters due south of Jaya Island.
By ten o'clock, the southern sea was still calm, and Usopp began to grow suspicious. "That Cricket guy wasn't pulling our legs, was he? It's almost noon, and nothing's happened yet."
Nico Robin shook her head, continuing to leaf through the book in her hands. "No. As Noland's descendant, he wants someone to find Shandora, the city of gold that was blasted into the sky, more than anyone."
Just then-
Nami's face flushed bright red, and she cried out, her eyes sparkling with excitement.
Hearing her cry, Luffy and the others ran over. "What is it, Nami? Did something happen?"
"I figured out how the Knock Up Stream forms!!" Her voice trembled with excitement. "The Knock Up Stream doesn't appear out of nowhere. It's an extreme natural phenomenon!"
Nami quickly grabbed a pen and circled an area on the sea chart, then explained at top speed. "There's an active underwater volcano beneath the waters due south of Jaya Island! It constantly releases hot gases and geothermal energy, causing the surrounding seawater's temperature to rise sharply!"
Her pen moved across the chart as though it could depict the volcano beneath those waters. "Because of the unusual crust structure around the crater, the energy it releases gets trapped inside an underground cavern, like a tightly sealed pressure cooker!"
Nami grew more and more excited. "When the underwater pressure reaches its limit, the entire cavern becomes a giant water cannon filled with highly pressurized water! Then-bang!!!" She swung her arms sharply, miming an enormous pillar of water shooting skyward. "All that energy erupts in an instant, creating the Knock Up Stream we see!"
"Quick,