In freestyle swimming, snorkels can be extremely beneficial in concentration of the head up during practicing the body rotation. With a snorkel, there is no need to rotate the head since you are breathing continuously so your focus is on the bottom of the pool. It helps to be in a more prone position and in turn improves stability. Furthermore, it also allows rotation of shoulders which rotates the hips and feet all without the concern of breathing which makes the transition to freestyle swimming more graceful.