Fluid dynamics of popping largest water splashes in Manu jumping

Manu jumping is a popular recreational water sport among the Māori people of New Zealand, known for creating large splashes upon water entry. Manu jumpers execute aerial maneuvers to form a V-shape upon impact with the water. Once submerged, they extend their bodies by rolling back and kicking outwards, increasing the air cavity's size and delaying its pinch-off. Collectively, these dynamics contribute to generating larger splashes. In this study, we investigate the fluid dynamics of Manu jumping through humans data (YouTube), passive solid objects, and an actively controlled robot. We investigate the role of impact speed, cavity size, and pinch-off time on the resultant splash height. We designed a robotic model (Manubot) to control its active opening inside the water to study the role of body-opening dynamics of human jumpers on splash size. Combining biomechanical data from human Manu jumpers and fluid dynamics of water entry of passive solids and the Manubot, we identify optimal parameters—such as V-angle, impact speed, and cavity size—for maximizing splash size. This work not only enhances scientific understanding of Manu jumping but also provides recommendations for safe practices in this sport.