An adjustable self-leveling boat bumper system attaches to a nautical structure associated with a body of water, and includes a longitudinal main guide, a longitudinal adjustment guide connected to a float element, a receiver, a boat bumper connected to the receiver, and an adjustment lock. The main and adjustment guides are oriented perpendicularly to a water surface. The receiver includes a main guide aperture and an adjustment aperture. The main and adjustment guides are moveably engaged with the main guide and adjustment apertures, respectively. The lock determines whether the adjustment guide is moveable. The float element provides a buoyancy force that maintains the receiver and float at a particular position along the main guide relative to the tide level of a body of water.