The hightech catamarans that are competing nowadays in the America’s Cup don’t have anything in common with ordinary boats. The so-called “hydrofoils” allow them to fly. Oracle Team USA, the title defenders of the America’s Cup, describe the process of “foiling” and name the advantages of it during a race. Video published on Jul 13, 2016.

Source : http://www.sailingscuttlebutt.com/2016/07/13/americas-cup-hydrofoils-101/