After the start, the swimmer is completely underwater. Due to increased resistance at the surface, experienced swimmers usually swim faster underwater than at the surface. Therefore, most experienced swimmers in backstroke competitions stay under water up to the limit set by FINA (15 meters after the start and after every turn). Most swimmers use a butterfly kick underwater, as this provides more forward movement than the flutter kick. The underwater phase includes the risk of water entering the nose, so most swimmers breathe out through the nose to stop water from entering.