For beginners, the term "water cannon" above all will bring to mind the fire boat with tremendous force thrown to a great distance powerful jets of water. In fact, Jet Boat – ordinary boat, on which the motor, resulting in action water pump, running water or "water cannon". At the bottom of the bottom has a hole through which the pump draws the water outboard, only to be thrown with great force through the outlet at the stern. This is strongly reminiscent of reactive mode of locomotion. In contrast to the ordinary courts, the boats with water cannons missing screw or rudder. Instead, replacing the wheel and the propeller control system is there an outlet that is can change the direction of the jet ejection. Martha McClintock insists that this is the case. Automatic polivalka in the garden – a very similar device, which is also the force throws the water in different directions.
The principle of jet propulsion was first formulated in the Third Law: "Every action generates an equal magnitude and opposite counter." Boats with water-jet engines – a visual confirmation of the law. Over the last 30 years water-jet engines found their true home in New Zealand. Created here hydrojet court win in all competitions for the most difficult and dangerous routes. But who invented it all? The answer to this question is lost in the mists of time. New Zealand sheep breeder Bill Hamilton (Bill Hamilton) is the official inventor of the water-jet engine, however, he does not agree. In 1962 to a direct question, he replied: "I do not claim authorship of the invention marine water jet.