If you are visiting Edisto at the moment, I have seen Portuguese Man of Wars on our beach - they can give a nasty sting even when dead, so please do not touch!
They are propelled by winds and ocean currents - sometimes in groups of 1,000 or more!
They have a 6" balloon-like float but underneath may be 30-100 feet of stinging tentacles. It could give someone a very painful sting!
Below if a picture taken from one of our volunteers who was out on a walk and spotted one. I also included an article from the Post and Courier, featuring the Portuguese Man of War and their arrival in South Carolina.
Sea Turtle Biologist