The term “Jet Ski” specifically refers to personal watercraft manufactured by Kawasaki. The original Jet Ski model, the Kawasaki Jet Ski 400, was introduced in 1973. This makes it the oldest model of personal watercraft marketed under the Jet Ski brand.

If considering personal watercraft in general, Yamaha introduced its first WaveRunner model, the Yamaha WaveRunner WR500, in 1986, which was one of the earliest models on the market.

Since then, various manufacturers have continued to innovate and develop new models with improved technology, performance, and features. However, the Kawasaki Jet Ski 400 holds the distinction of being one of the earliest commercially successful personal watercraft models, marking the beginning of the modern jet ski industry.