In competitive swimming, what is the start technique used for races?

The start technique used for races in competitive swimming is the block start. This technique involves swimmers beginning their race from a starting block, typically positioned at the edge of the pool. The swimmer crouches on the block, gripping the front edge in preparation for the start. When the race starts, they dive off the block into the water, aiming for a streamlined position to maximize speed.

The block start is critical in competitive swimming because it allows swimmers to achieve maximum velocity right from the outset of the race. It sets the tone for their performance and can significantly impact overall race times.

Other techniques, such as the dolphin dive, flip turn, and cannonball entry, serve different purposes in swimming. The dolphin dive is a technique often used during the start of an underwater phase, but it is not the primary method for initiating a race. The flip turn is a turn technique when approaching the wall, vital for maintaining speed in freestyle events but unrelated to the starting phase. The cannonball entry is more of a playful or recreational entry into the water often seen in casual swimming but not suitable for competitive starts. Thus, the block start is clearly the most appropriate technique used during races in the context of competitive swimming.