PURPOSE: To provide a stepping boat which has a fish body shape whose tail portion is moved right and left and which is advanced by means of a fin provided at this tail portion.

CONSTITUTION: A human power driving boat is provided with an operation seat 6b at the front of a main body 2 that is shaped like a fish body; a motion conversion device consisting of a link mechanism 5 at the rear; and a stepping type drive device 4 at the front of the operation seat 6b, and a first link 14 that converts the rotary motion of this into reciprocation and constitutes the link mechanism 5, is turned, and the link mechanism 5 is connectingly driven by means of this turning movement, and a fin 3 fixed at the final link 18 of this link mechanism 5 is made to reciprocate.