Velella velella, little blue sail, by-the-wind sailor, is a multiorganism creature similar to jellyfish. they float on top of the water and hang tentacles into the water that have stinging cells on them. They are supposed to be mildly bothersome but not much more but I think people with allergies may react different. They come in two varieties; the sails on top are oriented two different ways. One variant the sail causes it to get pushed leftward of the wind, the other variant the sail orientation causes it to get pushed rightward of the wind. I think this is one that gets pushed rightward.
When they are just washed up they are a blueish purpleish clearish if that makes any sense. What I photographed here has been washed ashore a long time and has long since bleached out. Its consistency here is like really sun damaged cellophane plastic. I was looking for crabs and other marine life that lives in the sargassum when I found this.
heres a wikipedia link so you can see what they look like when they arent a sunbleached husk.
https://en.wikipedia.org/wiki/Velella
I don't pay attention to him. I think he is a clown.