The present invention relates to a monohull offshore drilling vessel comprising a hull with a bow and a stern and a moonpool extending through the hull, the hull having an upper deck. A firing line hoist system comprising a mast is mounted on the hull. A drill floor is provided at a firing line side of the mast, which covers a portion of the moonpool while the firing line extends through an opening in said drill floor. Furthermore marine equipment and drilling equipment for performing auxiliary operations for the drilling or drilling related operations is provided, which equipment is mainly provided in the hull of the vessel below the upper deck. According to the invention, the drill floor is flush with the upper deck.