Reducing the impact forces of water entry

As professional divers complete what's known as a rip dive, their hands remove water in front of the body, creating a cavity that reduces the initial impact force. The rest of the body is aligned to shoot through the same cavity created by the hands. Using the hands to create cavities in the water's surface is similar to the concept behind the fluid-structure studies that researchers are conducting using spheres.

from Top Technology News -- ScienceDaily https://www.sciencedaily.com/releases/2018/11/181120125955.htm