Please measure your own or child's foot length first in order to choose the appropriate size
【Easier to Kick and Less Fatigue】Short fins are best for most snorkelers becasue they’re easier on your leg muscles. You don’t need as much power with each stroke, and each stroke will be shorter relative to using longer fins.
【Easy to Practice With in a Pool】Many casual snorkelers will be accustomed to a swimming flutter kick, which requires short and fast strokes. That means kicking with a short fin will feel more familiar, and thus easier to get used to.