PURPOSE: To decrease propulsion resistance, so as to improve propulsion efficiency, by preventing flow, separation on the rear part front surface from being generated by means of a finned fusiform propeller pod in spiral rotating water flow in the rear of a propeller blade without any possibility that the propeller blade hits a shore reef or a shoal and is damaged.

CONSTITUTION: A propulsion device is provided with a fusiform propeller pad 12 suspended from a hull by a blade sectional shaped strut 11, and housing a propeller driving mechanism, a hub 13 for partially forming the fusiform part on the front part of this propeller pod 12, and to be rotated and driven by the propeller driving mechanism, and a plurality of propeller blades 21 provided on the periphery of the hub 13. Moreover, it is provided with a plurality of blade sectional shaped fins 25 radially protruding from the propeller pod 21 by taking the shaft center as the center, and including fins 25a protruding in the radial direction outward from the propeller blades 21.