A self-adjusting barrier incorporates a series of float units restrained between a primary wall, such as a bulkhead, and a secondary wall, such as sheetpile. The secondary wall may be braced to the primary wall. The float units slidably interconnect along adjacent edges to self-adjust along a perimeter, such as a marina or waterfront lot, based on the height of water within the chamber (stilling basin) provided between the two walls. Mechanisms for deterring vandalism and providing increased environmental integrity are also provided for select embodiments. Methods of employing the barrier are also disclosed.