In a large-tonnage ship, the larger the propeller, the better the power, yes.
To see the size of the ship, engine output power, high waterline, ship fluid resistance and many other factors, generally high-speed small propellers, low-speed large propellers, the former is suitable for ships with smaller tonnage 800rpm per minute, the latter 300-450 rpm, if the engine power is smaller medium freighters are generally 300 rpm, in fact, the higher the speed, the better mainly depends on the output power of the engine and the structure of the propeller will not waste power, Assuming that even if the power of the engine is high, the speed is high, and the blades are large, but the blade design is not suitable for high-speed water flow structures.
The displacement of the propeller is proportional to the speed of the ship, the propeller is a propulsion device, through its own rotation to generate a backward force of water, on the contrary, the ship will receive a forward force, this is the propeller propulsion.
The following factors affect the speed of the boat
First: the direction of the water flow and the speed of the water flow
Second: the size and number of propeller blades
Third: propeller speed
Fourth: the weight of the ship