Abstract: Disclosed is a vessel including a hull and a system providing an air lubricating layer between the bottom and water, including a cavity defined by sidewalls, a top wall and an interface plane, in which water mixes with air due the Kelvin Helmholtz effect. The sidewalls extend from a dagger-shaped nose section at the front end to the rear end of the cavity and diverge so a distance between the sidewalls increases along the length of the cavity when going in a rearward direction. The diverging cavities provide a stable air lubrication layer that covers a relatively large area of the bottom, so the number of cavities can be reduced. The alignment of the diverging cavities with the streamlines has relatively large tolerances so construction is simplified and can be carried out in a cost-effective manner. The diverging sidewalls lead to reduced formation of vortices and reduced drag.