Cover Page: Diary of Koby-Meppo, Vol. 17: "Helmeppo's Determination".

Summoning his own courage for the first time, Helmeppo not only defies but outright disowns his father.

(In an oversight, Morgan's axe is portrayed on his left arm, instead of his right.)

On their way down from Reverse Mountain, the crew is eaten by a giant whale.

As the crew heads down the canal stream towards the Grand Line, a loud roar rings out into the air. Usopp announces he can see a giant mountain in the way, but Nami dismisses it as they should have open sea ahead of them. Suddenly they discover the giant mountain is actually a large whale. The crew concludes that the whale most likely does not know they are there as it appears just like a wall and would not be able to see them with its eyes. They try to come up with ideas before they hit it, but to everyone's dismay, Luffy's way of stopping the ship via cannon works but the idea is to fire a cannonball at the whale. Going Merry's bow figure is broken off as it bumps in the whale. They wonder if it felt the cannonball and call it "stupid" if it did not. But as the crew try and get away from the whale, Luffy hits it in the eye with a punch for breaking off "his special seat", which angers the whale.

The whale spots them with its eye and Luffy threatens it to a fight - resulting in the ship being swallowed. Luffy, however, ends up on top of the whale and is wondering how to get free his crew. He pummels the whale's head as the whale begins to lower into the water. Luffy spots a metal hatch on the surface of the whale just before it submerges.

Inside the whale, the crew wonders if they've entered a dream since there is an island here, and they appear to be outside. As they get near to the island a giant squid appears and is harpooned. Sanji and Zoro comment there must be a man living here and hopes he is friendly. Meanwhile, Luffy finds himself inside a tunnel in the body of the whale.

Chapter Notes:
The Straw Hat Pirates finally makes it into the Grand Line.
A giant whale blocks Luffy and his crew from going farther.
Luffy's special seat is destroyed by the whale.
The Going Merry is eaten by the whale.
Luffy's special seat is destroyed by the whale.
The Going Merry is eaten by the whale.
Luffy stays on the top of the whale, while the rest of his crew members were eaten.
Zoro, Nami, Sanji, and Usopp find that they are still alive, and spot an island.