Practical Approach to the Added Resistance of a Ship in Short Waves

In this paper, various analytical and semi-empirical formulas for calculating the added resistance in short waves are critically revisited and the authors proceed with an improved formula introducing correction factors accounting for ship’s block coefficient, waterline’s flare angle, sectional local draught and Froude number,. Extensive validations of the proposed formula were carried out by applications to different types of ships. It is anticipated that the updated formula well captures the added resistance of modern ships in short waves and may be a valuable contribution to ongoing discussions about level 1 and level 2 methods for the estimation of minimum powering in waves in the frame of IMO MEPC.232(65).