You know the story of Steve Irwin, his chest was cut open by a sting rays fishing hook like tail. Although this was not the cause of death the tail also split Steves heart in half.
Be sure that while you head farhter out in to the water causiously i hope scan the sea bed for an unusual shap if you do happen to see a shape back off slowly. If you panic the sting ray if that shape was a sting ray will atack. So be very causious and do NOT PANIC. The sting ray does only atack if thretened. If you do get even the littlest poke from the ray no matter what go to the nearest medical sourse because sting rays also have a toxin the unleash that can be lethal. Remember be safe no matter were you are!!!