What is the significance of the underwater dolphin-kick transition during a swimmer’s start?

• A. Underwater phase is not important; sprint starts from breakout
• B. Underwater phase increases drag; shorten it
• C. The transition to breakout should occur immediately upon entering water
• D. Underwater phase contributes to speed with minimal drag; transition to breakout should be timed to maximize velocity and maintain propulsion

Answer: (D)

The key idea here is that the initial underwater phase is a major source of speed because you can push water backward with powerful dolphin kicks while staying in a streamlined, low-drag position. While submerged, your body presents the smallest frontal area and you’re not fighting surface effects like wave drag or air-water interface. That combination lets you accumulate velocity efficiently and maintain propulsion longer than you could once you’re breaking the surface.

Timing the transition to the breakout is about preserving that velocity and momentum. Start the surface strokes at the moment you’re still moving fast underwater, but you’re ready to convert that underwater momentum into forward propulsion on the surface. If you surface too early, you lose some of the underwater-generated speed and momentum; if you wait too long, drag increases as you lose streamlining and the pace of the kicks isn’t being translated into surface propulsion as effectively. The goal is to maximize velocity and carry the underwater speed smoothly into the breakout and the subsequent surface swimming.