Imuchakk Arc

The Imuchakk Arc is the third story arc in the Adventure of Sinbad manga series. It deals with Sinbad traveling to Imuchakk, meeting Hinahoho and his sister, Pipirika, as well as them trying to conquer the Valefor Dungeon.

Summary
After the end of the Baal Arc Sinbad sets off on a ship to explore the world and begin his journey. A blue haired man is trying to defeat a sea monster. With his one spear he throws it at the monster hoping that it will die but it doesn't even scratch him. (Can someone else finish the summary for me?)