Abstract: A retractable perimeter barrier for a swimming pool including a plurality of panels each vertically movably positioned in edge-to-edge orientation within a trough. The trough is generally U-sectioned open along its margin and buried in upright position within the ground or deck area adjacent a swimming pool. Each panel includes a lower buoyant section of sufficient buoyancy to uprightly support the portion of the panel which extends above the buoyant section above the ground or deck within the trough when the trough is filled with water. Each panel will automatically retract or lower into the trough when water is drained therefrom. Water is preferably drawn from and returned to the swimming pool to fill and drain the trough.