A start is required at the beginning of every race. Backstroke and medley relay events start in the water, but all freestyle, breaststroke, butterfly, and solo medley events need a dive. Swimmers will enter the blocks for starts on the block when the referee blows one prolonged whistle. Once everyone is ready, there will be a signal to begin the race, and competitors will plunge in. When instructed to “take your mark,” the swimmers will position themselves for the beginning of the procedure, pushing off the wall as soon as the starting signal is heard. A swimmer is instantly eliminated from the competition if they dive into the water before the beginning signal.
Individual swimmers must finish the whole race length, whereas relay distances are evenly shared among the relay team members. Swimmers must stay in the same lane for the period, and all turns must be completed with a direct touch off the wall. Swimmers may not touch or push off the pool’s bottom. In terms of pool size, it must be 50 meters long with eight 2.5-meter wide lanes.
Swimmers cannot wrap their toes over the pool’s gutter or the top of the touchpad during the backstroke start. Except for the one stroke allowed within the flags to complete a flip-turn, they must swim the whole race on their back. The swimmer must emerge from the water within 15 meters and finish the race by hitting the wall on their back. Swimmers are not permitted to swim on their backs at any time during the butterfly start. Both arms must be propelled forward simultaneously, as must both legs in a downward motion. All swimmers must use both hands to touch the wall at each turn and at the end of the race. Swimmers are permitted one butterfly kick under the water’s surface between starting or turning and breaching the surface. During the race, the swimmer cannot depend on their back. The feet must be turned outward on the kick, and no downward kicks are permitted after breaking the surface. The swimmer must make two-hand contact with the wall at each turn and the race’s finish.