Drifting forces between two peak scattered bodies in waves

The purpose of the present paper is to extend the nonlinear theory of a single ship to the estimation of the drifting forces between two ships in waves. Basically the ships are assumed to be two weak scatterers and a simplified analytical method can be a two-dimensional source distribution method including the effects of the interaction between two ships. The nonlinear forces are expressed as products of the ship motion responses, the oscillatory potential and the incident wave potential which are all first order quantities with the interaction. Numerical results have been calculated for the Series 60 and Mariner ships. The comparison between the present results and those of near-field method is made and the similar trend is obtained. The results show that the present method with weak scatterer assumptions may also be regarded as a convenient tool to predict the nonlinear forces between two ships.