The propeller on a boat uses the same concept as the propeller on a plane. Boat propellers are available in various styles and designs. Boat propellers usually consist of two, three or four blades. Propellers for most pleasure boats are three- or four-bladed, but two- bladed propellers are frequently found on auxiliary sailboats and small outboard motors. These blades push water backward, and the boat moves forward as the disturbed water pushes back.
It is important to use the right propeller for your boat. With the right propeller your boat will be a joy to operate, an agile, responsive rig running at top efficiency. You may be wasting power or losing speed if you don’t know how to choose the right propeller for your boat. When choosing a propeller, it needs to match the engine’s power and shaft speed, and it must match the size and operating speed of the boat.