Episode 323

"Departure from the Water City! The Distinction of a Man, Usopp's Duel" is the 323rd episode of One Piece.

Summary
As the Straw Hat Pirates set to depart from Water 7, Garp, who is under watch from Aokiji, is attacking them with cannon balls that he is throwing at them. Chopper senses that Usopp is on shore trying to get their attention, but due to a conversation about honor they had earlier with Zoro, they don't stop for him. Usopp realizes what he must do as he begs for Luffy's forgiveness.