One Piece Chapter 1, page 43-45: Romance Dawn

Luffy thrashes in the water, unable to swim: "Jerk!! Brat... That guy is scum! And I didn't even get one punch in! Darn it!" Higuma watches him drown from the boat, laughing: "Ha ha ha ha ha!! Did you see the look on those pirates' faces? I broke a bottle over his head, and not one word of protest!! How pathetic!! Ha ha ha ha ha!! Cowards like that make me sick! I wanted to kill him!" Luffy screams back through the water: "Take that back! Take back what you said about Shanks!! He's not a coward!! Stop talking bad about Shanks!!!!

Suddenly, a massive shadow looms over Higuma's boat. A giant sea monster, the Lord of the Coast, rises from the water with a deafening roar. Higuma gasps in terror: "What... the-- AAH!!" Before he can react, the sea monster chomps down, completely devouring Higuma and smashing his boat to splinters. Luffy watches in horror as he continues to sink: "Glug glug

The sea monster turns its attention to Luffy, who is desperately splashing: "Glug! Somebody help me!! Glug! Glug!" The monster lunges forward, its massive jaws wide open to swallow the boy. Just as its teeth are about to close, Shanks appears in the water, grabbing Luffy and pulling him close to his chest.