Photo of a jellyfish taken at Atlanta Aquarium (GA, USA). This particular one is a Pacific sea nettle or Chrysaora fuscescens, they lives in the pacific coast of North America. The jellyfish are very common in many shores and usually are poisonous. Many of them have are very colorful. These organisms are carried by the sea currents however they have a system of self propulsion, for that they use their gastric system as a water jet.
At first I have thought you have started under-water photography:)
Well, I have a scuba diving license. But I am not into underwater photography.