How do jet drives compare with underwater propellers for efficiency?
Boats with waterjet propulsion are generally more efficient above 20 knots in hulls optimized for jets. Propellers are generally more efficient than jets in boats designed to operate at less than 20 knots. However, in some applications the attributes of waterjets, such as bollard pull, maneuverability, shallow-draft, and safety considerations override efficiency, especially if when little time is spent a the lower speeds. 5. I have heard that jet boats are less efficient and have poor performance? It is true that there have been unsuccessful jet boats. The poor performance of these boats can usually be identified as: • The jet was selected on price rather than selecting a model with the thrust needed to carry weight of the boat, full fuel, full passenger load, owner’s gear, and equipment. • There was a misunderstanding of the power actually available to the jet(s) when considering mission variables and transmission losses. • The selection was initially correct for the specified displac
