Amplitudes and phases of pitching and heaving of three models having simple mathematical ship forms in regular head waves are calculated by the strip method. The solutions to the coupled and uncoupled motions are obtained, and their results are compared. Resistance increases of the models in regular head waves with three different wave lengths are also calculated by Maruo's approximate method. A modified method taking into account the effect of forward speed on the vertical velocity of ship sections are also examined. The motions of the same models as well as the resistance increase in waves are measured and the results are compared with these calculations.