One Piece, Volume 38: Rocketman!!

Synopsis

After finding out the real reason for Robin's betrayal, the Straw Hats are in a madcap race to rescue her from CP9, the Navy's elite assassin group. But first they'll have to find a way to sail through the tidal wave known as Aqua Laguna. Will the Rocketman be seaworthy for the task at hand, or will it be a runaway train to catastrophe?!