Watercraft propulsion systems primarily fall into two categories: those that use an impeller to create thrust by accelerating a large volume of water moderately, and those that generate thrust by expelling a smaller volume of water at significantly higher velocity. The first method typically involves a submerged propeller connected to a drive shaft, while the second employs an internal impeller and nozzle system.
The choice of propulsion significantly influences a vessel’s performance characteristics, affecting speed, maneuverability, fuel efficiency, draft, and maintenance requirements. Historically, propeller-driven systems have dominated the maritime industry due to their relative simplicity and efficiency at lower speeds. However, advancements in impeller and engine technology have made jet propulsion increasingly viable, especially in applications demanding high speed, shallow draft, or enhanced maneuverability.