I must admit that I found the sign warning of Sting Ray Hop in the previous post, of interest, definitely something I've never seen before.
I imagine you shuffle your feet instead of directly stepping as a way of preventing a sting ray attack.
Anyway, I looked it up and this is what I found on ehow.com.
Sting rays rarely attack, but don't like being stepped on (me neither). "The ray's instinctive response will set you to hopping. These are "steps" you should take to avoid a painful experience:
1. Pay attention to posted signs, especially if you are the first one in the water.
2. Do the shuffle. It is difficult to spot a ray even in clear water because they settle into the sand. Instead of stepping, shuffle your feet forward to avoid stepping on one.
3. When snorkeling or diving, avoid the ocean floor If a ray feels threatened it is liable to strike with its tail.
4. Death is rare, but even a small barb in your foot can be dangerous.
Maybe someone should come up with a song called "The Sting Ray Shuffle."
To Step or To Shuffle? --RoadDog