Chapter 235 is titled "Knock Up Stream".
Luffy is finally back. During his fight, the Going Merry has been transformed into a chicken-like boat. After saying thanks and farewell to Cricket, they depart to the Knock Up Stream area. After several hours of calm, a Millennium Cumulonimbus is finally approaching. With the help of their diving crew, Masira and Shoujou are able to locate the stream. They then tell the Straw Hat Pirates to go toward a giant whirlpool that just has been created. The Going Merry has to reach the center of the whirlpool. Now it is too late to go back.
Nami is frustrated that Luffy hasn't returned, indicating that he's 46 minutes late and they won't make the Knock Up Stream in time if he doesn't hurry. She resolves that he's probably late because he didn't think about how carrying the gold would affect his time, but Sanji and Usopp are in agreement that calculating time is something Luffy would never consider. Chopper suggests that he could have been beaten, to which Nami replies she'd never forgive him for even if he was on time. Just then Luffy returns, proudly holding up a Hercules beetle (that he aptly named Hercules), confusing everyone present. He is then awestruck at the newly refitted Going Merry, furthering Nami's annoyance with him. After returning Montblanc Cricket's gold to him, he urges the Straw Hats to hurry to the ship. Luffy tries to thank him for the ship, but Cricket tells him to thank Masira and Shoujou instead. Luffy does so and offers them Hercules, much to their appreciation. They however also urge him to hurry to the ship, as time is limited. As Luffy runs to the ship, Cricket reflects on all the times that the "City of Gold" has been laughed off as his ancestor's imagination. He then shouts to the Saruyama Alliance not to screw this up, and to give it their all for Straw Hats. Luffy smiles at this, and finally boards the ship to set sail. As they prepare to head off, Cricket tells Luffy that one thing is certain: No one has ever proven that the City of Gold and Sky Island do not exist. He then wishes the Straw Hats a safe adventure, and they finally depart.
Aboard the Blackbeard Pirates raft, they are still in search of Luffy. Blackbeard mentions how Luffy indicated he's going to Sky Island, and that they must catch him before then or it will be tough to track him down.
Masira and Shoujou remind everyone that is 7:00 a.m., and they should be reaching their destination around 11 a.m. Reiterating how the Knock Up Stream's exact location is different every time, they emphasize that they must get there early to search for its exact position. They try to explain further how Luffy's tardiness impacted this, but they notice he is not paying attention, fooling around with the South Bird. He keeps turning the bird's head to see if it will stay in a different direction other than south, but to his amusement, it keeps springing its neck to face south. It gets highly annoyed at Luffy's antics and tells him (translated by Chopper) that he will turn a different direction to throw the pirates off. He turns north, but he is clearly straining himself to do so, and eventually has to face south again, causing more laughs from Luffy and Usopp. Luffy's carefree attitude about their schedule annoys them slightly, but they agree that worrying about it will do them no good and they press on.
3 hours later, they notice the Millenium Cumulonimbus cloud approaching them from the southwest. It is an hour early, but the Saruyama Alliance takes the necessary action regardless, and sends their scuba divers in to search for the stream. Shoujou uses his sonar ability to evaluate their surroundings. There is strong sea current directly ahead (12 o'clock), a Sea King directly to their right (9 o'clock), and slightly to the northwest (10 o'clock) there are giant waves, indicative of a large whirlpool. Masira exlaims that is it, and tells them to steer in the 10 o'clock direction. He states that the whirlpool and huge waves are sign of the pending explosion that creates the Knock Up Stream. The tumultuous waters instantly concern the Straw Hats, and Robin asks Nami to check the Log Pose. Like before, it is pointing straight up to the clouds. Shoujou and Masira both comment on how perfect the conditions are for the Knock Up Stream, and Luffy asks if they can get there. They assure him they can, and begin pulling the ship in the right direction themselves. The whirlpool has now become extremely large, as the brothers tell them that they actually have to make it to the center. This generates mixed reactions from the crew. Nami instantly freaks out, as it was never explained to them that they'd have to travel to the center of a gigantic whirlpool. Chopper seems excited at the prospect of their ship flying through the air, Robin simply comments on the size of the whirlpool, and Sanji promises to protect the ladies. Usopp is freaking out as well and wants to turn back, but Zoro tells him it is too late, as Luffy is extremely excited to finally make it to Sky Island.
- Luffy finally returns from his battle with Bellamy.
- The Going Merry has been refitted to deal with the extreme conditions surrounding the Knock Up Stream.
- Blackbeard wants to catch Monkey D. Luffy to become a Shichibukai.
- He is aware of their intentions to go Sky Island, and wants to catch him before he makes it.
- The Straw Hat Pirates depart for the Knock Up Stream.
- They are sucked into a giant whirlpool, as apparently this is necessary to ride the stream.