A blackball is a flag on a lifeguard tower or other highly visible area to show surfers that they must clear the water. A blackball flag is represented with a black circle in the center of a yellow or red flag; a yellow background being the most common. The flag is designed to protect swimmers from potentially harmful surfboards that may be moving at velocities after a "wipe out" from a wave. Swimmers maintain that the policy is a safety measure, while many surfers contend that blackball is an attempt to cull the in-water population in certain zones, providing preferential treatment to swimmers over surfers.
Newport Beach, California has regular headlines regarding the use of blackball[1][2][3][4] and dedicates a section of their official government site to the issue.[5]US House Representative Dana Rohrabacher[6] and Southern California politician Michael B. Glenn[7] have both made campaign issues out of the blackball implementation. Rohrabacher noted that Newport Beach was the only city who practiced blackball and also did not have a dedicated area for surf use.