You may see this type of sea creature as you walk along Jacksonville Beach or swim in the Atlantic Ocean in North Florida. Everyone seems to be afraid of these jellyfish because we all ask the same question: "JELLYFISH STING, don't they?" Well, here is some information below to clear up this issue and to assure you that these beautiful creatures are harmless to most.
The Cannonball jellyfish, also known as the cabbage head jellyfish, is a mostly harmless (it’s edible if you know how) variety that sometimes washes up on beaches in large numbers. It is shaped like half an egg and may be up to 7 inches in diameter. It may be bluish or yellowish with a brown border. It is a good swimmer.
The venom of the cannonball can give a mild sting, but generally, brushing against this jelly isn't enough to result in a sting. It goes without saying, that what would be a mild sting on the skin will be a very strong sting if the nematocysts get into your eyes. ~info provided by BeachHunter.net
So there... enjoy the beach this summer and worry about something else... or better yet, don't worry at all!