A ship propeller is a mechanical device that converts rotational energy into thrust, allowing a vessel to move through water. Typically made of metal or composite materials, propellers have blades that spin around a central hub. As the blades turn, they push water backward, creating a forward motion for the ship. Propellers come in various designs and sizes, depending on the type of vessel and its intended use. For example, larger ships like cargo vessels may have multiple blades for greater efficiency, while smaller boats might use simpler designs. Proper maintenance of ship propellers is essential for optimal performance and fuel efficiency.