The series of articles on Jettender design details by Agilis
A propulsion system is exactly that thing which gives a life to the boat and make it go. If the engine is a heart of the jet boat, then the propulsion system is its circulatory system. Usually it consists of the engine, gearbox, shaft, rudder and propeller.
There are many different drive types, but the most usable for small boats are a jet and Sterndrive systems when using inboard engines. The first one being inside the hull uses the water to push the boat streaming it through itself, the second one moves through the water with the help of a propeller placed outside the hull. Both of them has their advantages. Propeller makes a power transfer from the engine to the water very efficient and helps the Sterndrive boats to track smoothly at all speeds. On the other hand, in jet propulsion systems water enters in pump through an intake on the bottom and shoots as a high-velocity stream from the back. This system is safer, since there are no propellers which can harm the swimmers or be damaged while beaching. Thanks to the inside location of the whole system jet tender has minimal draft and can operate in shallow water. That`s why we choose jet pumps to our tenders.
Hence, we have determined the advantages of jet propulsion system over Sterndrive, let`s learn more about it. So, we already know that jet boat is propelled by a power of high-pressure water forced out of the stern of a vessel. A quantity of water accelerates moving through the pump located above the waterline during planning within the boat hull. Thereby, the propulsion power is created by the water jet in the nozzle. The most obvious advantages of jet motors are shown not even in design, but in motion and handling. Tenders with the jet propulsion system hold perfectly even on the tightest turns on the speed. That smoothness on tight turns is provided by the quick reaction of directional nozzle. Thus, control of jet tender is easy, agile and smooth.
We choose power, comfort and safety for our jet tenders, that`s why we select jet drive for them.