Chapter 605

Chapter 605 is called "The kraken and the pirates".

Short summary
Luffy and Co. arrive at the Kraken and foolishly aim to tame it. Usopp is startled by the Kraken and tries to convince Luffy to give up his ridiculous idea with Chopper mentioning that it has been alive for hundreds of years, being considered almost "mythological". Coribu's ship then arrives from behind, and is annihilated by the Kraken. Luffy, Sanji, and Zoro then get lifesuits named "Barefoot Coating" and set out to tame the beast. While the crew is dodging the Kraken, Luffy enters Gear 3 and hardens his enormous fist with the "Color of Armaments" Haki, while Sanji and Zoro run interference with their respective strengths. Luffy blows away the Kraken with his gigantic fist, and a shark pops out from under the Kraken. The Crew, with Luffy, Sanji, and Zoro on the outside, get sucked into the trench and end up in the Deep Sea, considered the "Underworld" of the sea.

Chapter notes

 * This is the second time that some of the Straw Hat Pirates go diving outside the ship, the first during the Jaya Arc. Coincidentally they are the same people: Luffy, Zoro and Sanji.
 * Sanji, for the first time since their reunion, doesn't get a nosebleed from looking at Nami (who was wearing a coat over her bikini top).
 * The Caribou pirates ship is destroyed by the Kraken.
 * Franky shows one of his weapons, which is a rocket launcher, and another one of his upgrades, which is nipple lights.
 * Chopper's Guard Point makes his fur even larger, large enough to block a Kraken's tentacle.
 * Luffy's use of the Busoshoku Haki seems to change the color of his skin.
 * Zoro has new secret technique named "Crossing of six Paths" aside from Three Thousand World.
 * Sanji uses a technique that resembles Geppou.
 * Robin for the first time use a "Mil Fleur" Technique
 * This is also the second time that someone exits from the mouth of a sea creature that has just been defeated with a punch, the first being Pappug and Keimi in Hatchan's cover story.
 * Luffy, Zoro, and Sanji are separated from the rest.
 * The Straw Hat Pirates make it 7,000 meters below sea level, 3,000 meters away from Fishman Island.
 * The shark wear a shirt similar to Keimi's