Poster: The Hydrodynamics of High Diving

Abstract

When a high cliff diver enters water after a 27m-high jump, he/she has to face three main risks of injuries: first the violent impact with water surface, which forces him/her to enter the feet first: then a stretching force between his/her two legs, against which he/she has to be muscularly prepared; and finally a local increase of pressure when the air cavities collapse. In this study, the high speed imaging of the diver motion underwater, and especially the shape and dynamics of the air cavities he/she entrains crossing the air/water interface helps us to understand the hydrodynamics underlying the risks of injuries threatening the divers. Both in the lab water tank and in a real training pool, we managed to fix in time beautiful and unthinkable pictures of underwater air cavities surrounding divers' legs.