The Upper Body Pulls the Lower Body

A bad habit with the track-start position is the back leg is often used to push. Pushing the body off the starting platform causes the center of mass to rotate forward and down. The top half of the body is hurled forward with the head usually leading the way. Especially if the arms start pointing down at the water.

This is pretty good height for a track-start position, but still not as effective as the PowerStart.  Also notice the position of the arms, they are pointing out.  The head is in-line with the spine and the arms are in a tight streamline.

 Another PowerStartsTM Secret 

The secret is to reach up-and-out with the arms. Don't let the arms point down at the water until just before entry. Reach out in front as far as possible with the arms stretched out leading the way. The longer the stretch the more the weight of the body will come forward and will cause your seesaw to tilt at the proper time for the correct angle of entry into the water. You may have to pike the hips to help get the proper angle.