Abstract: Disclosed is a dual cavity air lubrication system including an air flow splitter with an air inlet pipe branching into a first branch pipe and a second branch pipe, wherein a first passive valve is arranged in the first branch pipe and a second passive valve is arranged in the second branch pipe, wherein the branch pipes are in fluid communication with each other upstream from their respective valves, and wherein the valves are adapted for regulating the flow of air to respective air cavities to compensate for difference in air pressure in the cavities caused by a relative change in level of the cavities due to roll or heel of the vessel.