A small planning boat includes a filler opening for a fuel tank and an opening section that are formed on the deck of the boat body. The filler opening and the opening section are covered with a hatch cover when the hatch cover is closed. A fuel-receiving concave section is formed around the filler opening, so that the filler opening is positioned at the bottom surface section of a fuel-receiving concave section. A guide groove that declines downward from the bottom surface section on an outer side of the boat body can be formed as one piece with the fuel-receiving concave section. A storage section can also be formed inside the opening section. In addition, the filler opening can be positioned on the starboard side rearward from the opening section, and the guide groove can be formed in a section on an outer side of the opening section.