In order to save Luffy from drowning, Sanji jumps into the sea. He is relieved when he sees that Nojiko and Genzo have already saved him by stretching his head out of the water. However Luffy is still unconscious and prisoner of the rock boulder. Unfortunately Sanji's respite is short, since Kuroobi joined him in the water. Indeed, the shark has the advantage undersea and starts to attack the cook who is unable to counter. When Kuroobi notices the two villagers, he wants to kill them too, but Sanji has not said his last words and stops him. Angry with this futile move, Kuroobi goes berserk on Sanji. With the water pressure change and the lack of oxygen, Sanji is at his limits. But on a clear-sighted move, he breathes air into the Fishman gills, which makes him impotent for a short time, but long enough for Sanji to reach the surface. Back on his element, Sanji is able to deploy his full skill and defeats Kuroobi in mere seconds.
Hatchan gets knocked out, and Zoro tries to jump into the pool, but is stopped by Sanji, who jumps in himself and is followed by Kuroobi, Sanji then notices that Genzo and Nojiko are already helping out and that Genzo is performing CPR on Luffy. Sanji then tries to break the rock that Luffy is trapped under, but is stopped by Kuroobi who attacks him and then tries to stop Genzo, but is in turn stopped by Sanji, and they began to fight. At first Sanji gets outclassed due to fishman karate's power being doubled under water, and he tries to get back to the surface to get some fresh air, but is stopped again by Kuroobi. Who continues to torment Sanji by carrying up then back down, which hurts Sanji immensely due to the change in pressure, but he doesn't give up, which leads to more punishment. Sanji then bites Kuroobi in the gills making him release his grip, freeing Sanji to get some fresh air, he then gets out of the water telling Zoro that Luffy is fine, and then demands that the fishman gets out of the water, which he does. They then continue to fight, this time with Sanji having the advantage, and in the end Sanji manages to overpower Kurrobi and win.