The paper theoretically investigates the propulsion power requirements for high speed catamarans in calm water. The power estimates, by themself, play an important role during the preliminary design stage of new high speed catamarans where the optimal geometric configuration of catamaran hulls from the perspective of propulsion power needs to be found.

Importance of the power predictions increases in particular when the catamarans are operating in the fast transportation profiles in coastal areas. This is mainly due to fact that the existence of the variable range of water depths can significantly affect the resistance and consequently the propulsive and operational range performances of a vessel. Therefore, the propulsion power requirements in the current study are predicted by taking into account the deep water and, as well as, the preselected constant finite water depths conditions.

The power analysis is performed by using a modified version of the Doctors and Days (1997) method. Modifications relative to outlined method lay in the fact that the wave resistance and free surface profiles, are numerically predicted with two different linear potential flow field theories applicable for deep and finite constant water depths; Michell’s thin ship theory without/with the viscosity effects and 3D Rankine panel method with an inclusion of the ‘staggered grid’ technique, respectively.

Based on the application feasibility of obtained numerical results in a catamaran preliminary design process, the adequate wave resistance models are selected and combined with the Doctors and Days (1997) method giving the total resistance and consequently the effective power of the cargo carrier high speed catamaran in interval of Froude numbers in deep water and at selected finite constant water depths. Finally, the concluding remarks concerning the behavior of the effective propulsive power in relation to water depths are outlined from the high speed catamarans preliminary design point of view.