Galle Fort Flag Rock cliff jumpers: ocean depth safety, coral reefs, and tipping customs?

At Flag Rock Bastion on the southernmost tip of Galle Fort, local professional cliff jumpers leap 12 meters into the ocean between breaking swells. Tourists should NEVER attempt this jump. The landing area is an extremely narrow, shallow channel flanked on both sides by submerged coral reefs and sharp granite boulders. Local jumpers time their leap precisely to hit the crest of an incoming swell when water depth momentarily reaches 3 meters. Jumping between swell sets or misjudging trajectory results in impact against the shallow rock bed.