CALM WATER EQUILIBRIUM, DIRECTIONAL STABILITY AND STEADY TURNING CONDITIONS FOR RECREATIONAL PLANING CRAFT

Abstract : Measurements of steady, symmetric and non-symmetric planing forces and moments on a series of prismatic hulls are tabulated and discussed. An analytical representation of the forces and moments due to an outboard engine is derived. Curve fits of the data together with the outboard engine representation are used to predict: (1) Straight course equilibrium conditions; (2) Directional stability of these equilibrium conditions with roll fixed; and (3) STeady turning equilibrium conditions. A comparison is made between these calculated results and measured turning diameter of a typical full-scale recreational planing craft. (Author)