| 摘要 |
PURPOSE:To prevent the adhesion of barnacles to a jet unit without landing a boat body at the unused time and reduce the damage of packing while keeping air from being drawn through the peripheral edge part of a water intake port. CONSTITUTION:A jet unit 3 disposed at the stern bottom is provided with a water intake port 31 opened below the water level, a rotating/driving motor 7 for rotating the jet unit 3, a hydraulic cylinder 6 for elevating the jet unit 3, a hydraulic pump for the motor 7 and hydraulic cylinder 6, and a passage control means 9a. Packing 38a is disposed between the peripheral edge part of the water intake port 31 and the bottom board. The passage control means 9a is formed in such a way as to drive only the hydraulic cylinder 6 when a gap between the water intake port 31 and the bottom is less than the specified quantity so as to stop the rotating/driving motor 7. |
