PURPOSE: To precisely perform the control from low-speed navigation to normal navigation especially with a single handle, concerning a propeller fitted with a handle operation type control system suitable for a vessel navigating at low speed in investigation water area, etc.

CONSTITUTION: This marine propeller is so constituted as to keep the fuel consumption rate of the main engine 9 optimum, by performing the control by the governor control means 14 of the main engine 9 and the control by a propeller pitch control means 12, through the normal navigation control circuit 15b in a combination control means 15, according to the operation position of a single handle 2, in condition that the main engine 9 is over the specified revolution. When this ship enters investigation water area and performs slow- speed navigation, the slow-speed navigation control circuit 15a in a combination control means 15 is used, and in condition that the main engine 9 is lowered to the specified revolution, the control by the propeller pitch control means 12 and the slipping control of a clutch 7 are performed, according to the operation of the handle 2.