As for the derivatives of Y'H and N'H, they may be the function of Cb, L/B, dem/B trim and so on. However, as plotted in Fig.10 and Fig.11 , the database shows the contributions except trim are so small, that they can be expressed as the following simple formulas of trim.

　

　

4.3 Interactive force coefficients among Hull, Propeller and Rudder

　

 The interactive force coefficients: (1-tR), αH, l'R (=lR/L), γR and ε are mainly expressed by Cb/(L/B) as shown in Fig.12, and described eq.(15) and eq.(16).

　

　

　

 These regression formulas, however, fully depend on the database. Therefore, the available ship dimensions must be clarified. In this analysis, the following limitations may be provided from the database.