The course-keeping stability of a high speed planing boat should be considered at the design stage for its safe operations. The shape of waterjet intake plane is one of important design parameters of a waterjet propelled planing boat. That has significant influences on the stern flow patterns and pressure distributions. In this study, the effects of the waterjet intake shapes of planing boats on the course-keeping stabilities are investigated. Two kinds of designed planing boats have the same dimensions, but there are differences in waterjet intake plane shapes. Captive and free-running model tests, Computational Fluid Dynamics (CFD) analyses are carried out in order to estimate their hydrodynamic performances including course-keeping stabilities. The results show that the flat and wide waterjet intake plane of the initially designed boat makes the course-keeping stability worse. The waterjet intake shape is re-designed to improve the course-keeping stability. The improved performances are confirmed by free-running model tests and full-scale trials.

高速滑行艇在设计阶段应考虑其航向稳定性，以保证其安全运行。水刀进气平面的形状是水刀推进滑翔艇的重要设计参数之一。这对船尾流型和压力分布有重大影响。在这项研究中，研究了滑行艇的水刀进水口形状对航向保持稳定性的影响。两种设计的滑艇具有相同的尺寸，但在水刀进气平面形状上存在差异。执行俘获和自由运行模型测试、计算流体动力学 (CFD) 分析以估计其流体动力学性能，包括航向保持稳定性。结果表明，初始设计的艇的扁平宽阔的水刀进气平面使航向保持稳定性变差。重新设计水刀进水口形状，提高航向稳定性。通过自由运行模型测试和全尺​​寸试验证实了改进的性能。