PURPOSE: To provide a manually propelling boat having an auxiliary driving source by which a planing condition not less than water separating speed can be realized and a manually propelling feeling is not spoiled.

CONSTITUTION: A manually driving system to drive a propelling machine in rotation by manual operation and an auxiliary driving system to drive the propelling machine in rotation by an auxiliary driving source, are arranged in parallel with each other, and a manually propelling boat having the auxiliary driving source is constituted so as to assist main driving force of the manually driving system by auxiliary driving force of the auxiliary driving system. In this case, the boat has a planing detecting means (to detect boat speed) 37 to detect the occurrence of a planing condition where the great part of a boat body floats from a water surface, an assist ratio control means (controller) 30 to control so that an assist ratio (auxiliary driving force/main driving force) in a non-planing area before the occurrence of the planing condition becomes larger than an assist raion in a planing area and an auxiliary driving source control means (controller) 30 to control an auxiliary driving motor 11 so that the auxiliary driving force becomes a value according to the assist ratio.