The Mitsubishi Air Lubrication System (MALS) was the first air lubrication system in the world to be applied to a newly built ship, and resulted in a substantial reduction in the ship’s resistance. Therefore, a performance estimation method using computational fluid dynamics (CFD) needs to be established as soon as possible to apply the MALS to general commercial ships. In this study, we predicted the bubble distribution around ships with the MALS using CFD, and developed a method to determine the reduction in flow resistance based on the bubble coverage around the hull. Furthermore, we also predicted the intrusion of bubbles on the area of propeller disks, which could deteriorate the performance, and confirmed that the deterioration in propeller disk performance was negligible.