PURPOSE: To ride as it is even though a riding apparatus is turned over, by installing and composing a pair of left and right almost spherical floating bodies near the rear side riding position rotatable through a horizontal shaft, to a boat body having an adequate floating force formed symmetrical laterally and vertically.

CONSTITUTION: A boat body 1 is formed of a material such as a plate having an adequate floating force, and it is formed symmetrical laterally and vertically. Floating bodies 2 and 2 are composed of a material such as a foam styrol having a floating force, and formed in a pair of the left side and the right side near the sitting position to the boat body 1, and rotatable through a horizontal shaft 3 inserted to the boat body 1. Furthermore, the floating bodies 2 and 2 are composed allowable to separate and asselble, and they can be separated in the transportation. And a running shaft 4 is provided at the front position of the boat body 1, and thereby, it can run on the ground.