Abstract
A slender planning ship theory without gravitational effect was proposed from a viewpoint of perturbation method. A asymptotic expansions of velocity potential near the hard chine of rectangular planing plate were constructed in both domains near and local near field. In the local near field, there was a self-similar flow along the hard chine and it showed that existance of homogeneous solution in the local flow field near the hard chine. The homogeneous solution was essential to represent this local near field where non-linear wave generated and it was identified to impose Kutta's condition strictly on the hard chine. This local flow field was solved to identify the homogeneous solution on the assumption that the non-linear wave was so small. and the result was compared with the Savitsky's formula which was derived from experimental data qualitatively. Some numerical methods to solve this local flow field were suggested and the subjects for numerical computations were pointed out.
