The history of waterjet propulsion began with a simple problem: propellers struggled in shallow water, where they could strike the bottom or lose effectiveness. Experiments date back to the 1780s with James Rumsey, but the technology became practical in the 1950s when New Zealand engineer William Hamilton developed a successful shallow-water system and, in 1954, moved the jet outlet above the waterline. His 1957 Chinook further improved efficiency with a twin-impeller axial-flow design. Waterjets soon found uses in military patrol boats, recreational craft such as the 1973 Kawasaki Jet Ski, and eventually high-speed commercial vessels like the HSC Francisco, which can reach about 67 mph. Although waterjets offer advantages in shallow draft, maneuverability, and high-speed applications, propellers remain more efficient for many vessels. Ultimately, waterjet propulsion evolved as an engineering solution to the limitations of conventional propellers rather than a universal replacement for them.
Learn about the big-block jet boats and the history of the Jet Ski.
